New demo class, very handy for interactive presentations.

IPython/demo.py

@@ -0,0 +1,115 b''
+"""Module for interactive demos using IPython.
+"""
+#*****************************************************************************
+#       Copyright (C) 2005 Fernando Perez. <[e-mail]>
+#
+#  Distributed under the terms of the BSD License.  The full license is in
+#  the file COPYING, distributed as part of this software.
+#
+#*****************************************************************************
+
+import exceptions
+
+from IPython.PyColorize import Parser
+from IPython.genutils import marquee
+
+class DemoError(exceptions.Exception): pass
+
+class Demo:
+    def __init__(self,fname,pause_mark='# pause',auto=False):
+
+        self.fname = fname
+        self.pause_mark = pause_mark
+        self.auto = auto
+
+        # get a few things from ipython.  While it's a bit ugly design-wise,
+        # it ensures that things like color scheme and the like are always in
+        # sync with the ipython mode being used.  This class is only meant to
+        # be used inside ipython anyways,  so it's OK.
+        self.ip_showtraceback = __IPYTHON__.showtraceback
+        self.ip_ns = __IPYTHON__.user_ns
+        self.ip_colors = __IPYTHON__.rc['colors']
+
+        # read data and parse into blocks
+        fobj = file(fname,'r')
+        self.src = fobj.read()
+        fobj.close()
+        self.src_blocks = [b.strip() for b in self.src.split(pause_mark) if b]
+        self.nblocks = len(self.src_blocks)
+
+        # try to colorize blocks
+        colorize = Parser().format
+        col_scheme = self.ip_colors
+        self.src_blocks_colored = [colorize(s_blk,'str',col_scheme)
+                                   for s_blk in self.src_blocks]
+
+        # finish initialization
+        self.reset()
+
+    def reset(self):
+        self.user_ns  = {}
+        self.finished = False
+        self.block_index = 0
+
+    def again(self):
+        self.block_index -= 1
+        self()
+
+
+    def _validate_index(self,index):
+        if index<0 or index>=self.nblocks:
+            raise ValueError('invalid block index %s' % index)
+
+    def seek(self,index):
+        self._validate_index(index)
+        self.block_index = index-1
+        self.finished = False
+
+    def show(self,index=None):
+        if index is None:
+            index = self.block_index
+        else:
+            self._validate_index(index)
+        print marquee('<%s> block # %s (%s/%s)' %
+                      (self.fname,index,index+1,self.nblocks))
+        print self.src_blocks_colored[index],
+        
+    def __call__(self,index=None):
+        """run a block of the demo.
+
+        If index is given, it should be an integer >=1 and <= nblocks.  This
+        means that the calling convention is one off from typical Python
+        lists.  The reason for the inconsistency is that the demo always
+        prints 'Block n/N, and N is the total, so it would be very odd to use
+        zero-indexing here."""
+
+        if index is None and self.finished:
+            print 'Demo finished.  Use reset() if you want to rerun it.'
+            return
+        if index is None:
+            index = self.block_index
+        self._validate_index(index)
+        try:
+            next_block = self.src_blocks[index]
+            self.block_index += 1
+            self.show(index)
+            if not self.auto:
+                print marquee('Press <q> to quit, <Enter> to execute...'),
+                ans = raw_input().strip()
+                if ans:
+                    print marquee('Block NOT executed')
+                    return
+            
+            exec next_block in self.user_ns
+            
+        except:
+            self.ip_showtraceback(filename=self.fname)
+        else:
+            self.ip_ns.update(self.user_ns)
+
+        if self.block_index == self.nblocks:
+            print
+            print marquee(' END OF DEMO ')
+            print marquee('Use reset() if you want to rerun it.')
+            self.finished = True
+

IPython/genutils.py

@@ -1,1530 +1,1540 b''
 # -*- coding: utf-8 -*-
 """
 General purpose utilities.
 
 This is a grab-bag of stuff I find useful in most programs I write. Some of
 these things are also convenient when working at the command line.
 
-$Id: genutils.py 874 2005-09-20 20:13:04Z fperez $"""
+$Id: genutils.py 894 2005-09-22 07:16:18Z fperez $"""
 
 #*****************************************************************************
 #       Copyright (C) 2001-2004 Fernando Perez. <[e-mail]>
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #*****************************************************************************
 
 from __future__ import generators # 2.2 compatibility
 
 from IPython import Release
 __author__  = '%s <%s>' % Release.authors['Fernando']
 __license__ = Release.license
 
 #****************************************************************************
 # required modules
 import __main__
 import types,commands,time,sys,os,re,shutil
 import tempfile
 from IPython.Itpl import Itpl,itpl,printpl
 from IPython import DPyGetOpt
 
 # Build objects which appeared in Python 2.3 for 2.2, to make ipython
 # 2.2-friendly
 try:
     basestring
 except NameError:
     import types
     basestring = (types.StringType, types.UnicodeType)
     True = 1==1
     False = 1==0
 
     def enumerate(obj):
         i = -1
         for item in obj:
             i += 1
             yield i, item
 
     # add these to the builtin namespace, so that all modules find them
     import __builtin__
     __builtin__.basestring = basestring
     __builtin__.True = True
     __builtin__.False = False
     __builtin__.enumerate = enumerate
 
 #****************************************************************************
 # Exceptions
 class Error(Exception):
     """Base class for exceptions in this module."""
     pass
 
 #----------------------------------------------------------------------------
 class IOStream:
     def __init__(self,stream,fallback):
         if not hasattr(stream,'write') or not hasattr(stream,'flush'):
             stream = fallback
         self.stream = stream
         self._swrite = stream.write
         self.flush = stream.flush
 
     def write(self,data):
         try:
             self._swrite(data)
         except:
             try:
                 # print handles some unicode issues which may trip a plain
                 # write() call.  Attempt to emulate write() by using a
                 # trailing comma
                 print >> self.stream, data,
             except:
                 # if we get here, something is seriously broken.
                 print >> sys.stderr, \
                       'ERROR - failed to write data to stream:', stream
         
 class IOTerm:
     """ Term holds the file or file-like objects for handling I/O operations.
 
     These are normally just sys.stdin, sys.stdout and sys.stderr but for
     Windows they can can replaced to allow editing the strings before they are
     displayed."""
 
     # In the future, having IPython channel all its I/O operations through
     # this class will make it easier to embed it into other environments which
     # are not a normal terminal (such as a GUI-based shell)
     def __init__(self,cin=None,cout=None,cerr=None):
         self.cin  = IOStream(cin,sys.stdin)
         self.cout = IOStream(cout,sys.stdout)
         self.cerr = IOStream(cerr,sys.stderr)
         
 # Global variable to be used for all I/O
 Term = IOTerm()
 
 # Windows-specific code to load Gary Bishop's readline and configure it
 # automatically for the users
 # Note: os.name on cygwin returns posix, so this should only pick up 'native'
 # windows.  Cygwin returns 'cygwin' for sys.platform.
 if os.name == 'nt':
     try:
         import readline
     except ImportError:
         pass
     else:
         try:
             _out = readline.GetOutputFile()
         except AttributeError:
             pass
         else:
             # Remake Term to use the readline i/o facilities
             Term = IOTerm(cout=_out,cerr=_out)
             del _out
 
 #****************************************************************************
 # Generic warning/error printer, used by everything else
 def warn(msg,level=2,exit_val=1):
     """Standard warning printer. Gives formatting consistency.
 
     Output is sent to Term.cerr (sys.stderr by default).
     
     Options:
     
     -level(2): allows finer control:
       0 -> Do nothing, dummy function.
       1 -> Print message.
       2 -> Print 'WARNING:' + message. (Default level).
       3 -> Print 'ERROR:' + message.
       4 -> Print 'FATAL ERROR:' + message and trigger a sys.exit(exit_val).
 
     -exit_val (1): exit value returned by sys.exit() for a level 4
     warning. Ignored for all other levels."""
     
     if level>0:
         header = ['','','WARNING: ','ERROR: ','FATAL ERROR: ']
         print >> Term.cerr, '%s%s' % (header[level],msg)
         if level == 4:
             print >> Term.cerr,'Exiting.\n'
             sys.exit(exit_val)
 
 def info(msg):
     """Equivalent to warn(msg,level=1)."""
 
     warn(msg,level=1)
 
 def error(msg):
     """Equivalent to warn(msg,level=3)."""
 
     warn(msg,level=3)
 
 def fatal(msg,exit_val=1):
     """Equivalent to warn(msg,exit_val=exit_val,level=4)."""
 
     warn(msg,exit_val=exit_val,level=4)
 
 #----------------------------------------------------------------------------
 StringTypes = types.StringTypes
 
 # Basic timing functionality
 
 # If possible (Unix), use the resource module instead of time.clock()
 try:
     import resource
     def clock():
         """clock() -> floating point number
 
         Return the CPU time in seconds (user time only, system time is
         ignored) since the start of the process.  This is done via a call to
         resource.getrusage, so it avoids the wraparound problems in
         time.clock()."""
         
         return resource.getrusage(resource.RUSAGE_SELF)[0]
     
     def clock2():
         """clock2() -> (t_user,t_system)
 
         Similar to clock(), but return a tuple of user/system times."""
         return resource.getrusage(resource.RUSAGE_SELF)[:2]
 
 except ImportError:
     clock = time.clock
     def clock2():
         """Under windows, system CPU time can't be measured.
 
         This just returns clock() and zero."""
         return time.clock(),0.0
 
 def timings_out(reps,func,*args,**kw):
     """timings_out(reps,func,*args,**kw) -> (t_total,t_per_call,output)
 
     Execute a function reps times, return a tuple with the elapsed total
     CPU time in seconds, the time per call and the function's output.
 
     Under Unix, the return value is the sum of user+system time consumed by
     the process, computed via the resource module.  This prevents problems
     related to the wraparound effect which the time.clock() function has.
     
     Under Windows the return value is in wall clock seconds. See the
     documentation for the time module for more details."""
 
     reps = int(reps)
     assert reps >=1, 'reps must be >= 1'
     if reps==1:
         start = clock()
         out = func(*args,**kw)
         tot_time = clock()-start
     else:
         rng = xrange(reps-1) # the last time is executed separately to store output
         start = clock()
         for dummy in rng: func(*args,**kw)
         out = func(*args,**kw)  # one last time
         tot_time = clock()-start
     av_time = tot_time / reps
     return tot_time,av_time,out
 
 def timings(reps,func,*args,**kw):
     """timings(reps,func,*args,**kw) -> (t_total,t_per_call)
 
     Execute a function reps times, return a tuple with the elapsed total CPU
     time in seconds and the time per call. These are just the first two values
     in timings_out()."""
 
     return timings_out(reps,func,*args,**kw)[0:2]
 
 def timing(func,*args,**kw):
     """timing(func,*args,**kw) -> t_total
 
     Execute a function once, return the elapsed total CPU time in
     seconds. This is just the first value in timings_out()."""
 
     return timings_out(1,func,*args,**kw)[0]
 
 #****************************************************************************
 # file and system
 
 def system(cmd,verbose=0,debug=0,header=''):
     """Execute a system command, return its exit status.
 
     Options:
 
     - verbose (0): print the command to be executed.
     
     - debug (0): only print, do not actually execute.
 
     - header (''): Header to print on screen prior to the executed command (it
     is only prepended to the command, no newlines are added).
 
     Note: a stateful version of this function is available through the
     SystemExec class."""
 
     stat = 0
     if verbose or debug: print header+cmd
     sys.stdout.flush()
     if not debug: stat = os.system(cmd)
     return stat
 
 def shell(cmd,verbose=0,debug=0,header=''):
     """Execute a command in the system shell, always return None.
 
     Options:
 
     - verbose (0): print the command to be executed.
     
     - debug (0): only print, do not actually execute.
 
     - header (''): Header to print on screen prior to the executed command (it
     is only prepended to the command, no newlines are added).
 
     Note: this is similar to genutils.system(), but it returns None so it can
     be conveniently used in interactive loops without getting the return value
     (typically 0) printed many times."""
 
     stat = 0
     if verbose or debug: print header+cmd
     # flush stdout so we don't mangle python's buffering
     sys.stdout.flush()
     if not debug:
         os.system(cmd)
 
 def getoutput(cmd,verbose=0,debug=0,header='',split=0):
     """Dummy substitute for perl's backquotes.
 
     Executes a command and returns the output.
 
     Accepts the same arguments as system(), plus:
 
     - split(0): if true, the output is returned as a list split on newlines.
 
     Note: a stateful version of this function is available through the
     SystemExec class."""
 
     if verbose or debug: print header+cmd
     if not debug:
         output = commands.getoutput(cmd)
         if split:
             return output.split('\n')
         else:
             return output
 
 def getoutputerror(cmd,verbose=0,debug=0,header='',split=0):
     """Return (standard output,standard error) of executing cmd in a shell.
 
     Accepts the same arguments as system(), plus:
 
     - split(0): if true, each of stdout/err is returned as a list split on
     newlines.
 
     Note: a stateful version of this function is available through the
     SystemExec class."""
 
     if verbose or debug: print header+cmd
     if not cmd:
         if split:
             return [],[]
         else:
             return '',''
     if not debug:
         pin,pout,perr = os.popen3(cmd)
         tout = pout.read().rstrip()
         terr = perr.read().rstrip()
         pin.close()
         pout.close()
         perr.close()
         if split:
             return tout.split('\n'),terr.split('\n')
         else:
             return tout,terr
 
 # for compatibility with older naming conventions
 xsys = system
 bq = getoutput
 
 class SystemExec:
     """Access the system and getoutput functions through a stateful interface.
 
     Note: here we refer to the system and getoutput functions from this
     library, not the ones from the standard python library.
     
     This class offers the system and getoutput functions as methods, but the
     verbose, debug and header parameters can be set for the instance (at
     creation time or later) so that they don't need to be specified on each
     call.
 
     For efficiency reasons, there's no way to override the parameters on a
     per-call basis other than by setting instance attributes. If you need
     local overrides, it's best to directly call system() or getoutput().
 
     The following names are provided as alternate options:
      - xsys: alias to system
      - bq: alias to getoutput
 
     An instance can then be created as:
      >>> sysexec = SystemExec(verbose=1,debug=0,header='Calling: ')
 
     And used as:
      >>> sysexec.xsys('pwd')
      >>> dirlist = sysexec.bq('ls -l')
     """
     
     def __init__(self,verbose=0,debug=0,header='',split=0):
         """Specify the instance's values for verbose, debug and header."""
         setattr_list(self,'verbose debug header split')
 
     def system(self,cmd):
         """Stateful interface to system(), with the same keyword parameters."""
 
         system(cmd,self.verbose,self.debug,self.header)
 
     def shell(self,cmd):
         """Stateful interface to shell(), with the same keyword parameters."""
 
         shell(cmd,self.verbose,self.debug,self.header)
 
     xsys = system  # alias
 
     def getoutput(self,cmd):
         """Stateful interface to getoutput()."""
 
         return getoutput(cmd,self.verbose,self.debug,self.header,self.split)
 
     def getoutputerror(self,cmd):
         """Stateful interface to getoutputerror()."""
 
         return getoutputerror(cmd,self.verbose,self.debug,self.header,self.split)
 
     bq = getoutput  # alias
 
 #-----------------------------------------------------------------------------
 def mutex_opts(dict,ex_op):
     """Check for presence of mutually exclusive keys in a dict.
 
     Call: mutex_opts(dict,[[op1a,op1b],[op2a,op2b]...]"""
     for op1,op2 in ex_op:
         if op1 in dict and op2 in dict:
             raise ValueError,'\n*** ERROR in Arguments *** '\
                   'Options '+op1+' and '+op2+' are mutually exclusive.'
 
 #-----------------------------------------------------------------------------
 def filefind(fname,alt_dirs = None):
     """Return the given filename either in the current directory, if it
     exists, or in a specified list of directories.
 
     ~ expansion is done on all file and directory names.
 
     Upon an unsuccessful search, raise an IOError exception."""
 
     if alt_dirs is None:
         try:
             alt_dirs = get_home_dir()
         except HomeDirError:
             alt_dirs = os.getcwd()
     search = [fname] + list_strings(alt_dirs)
     search = map(os.path.expanduser,search)
     #print 'search list for',fname,'list:',search  # dbg
     fname = search[0]
     if os.path.isfile(fname):
         return fname
     for direc in search[1:]:
         testname = os.path.join(direc,fname)
         #print 'testname',testname  # dbg
         if os.path.isfile(testname):
             return testname
     raise IOError,'File' + `fname` + \
           ' not found in current or supplied directories:' + `alt_dirs`
 
 #----------------------------------------------------------------------------
 def target_outdated(target,deps):
     """Determine whether a target is out of date.
 
     target_outdated(target,deps) -> 1/0
 
     deps: list of filenames which MUST exist.
     target: single filename which may or may not exist.
 
     If target doesn't exist or is older than any file listed in deps, return
     true, otherwise return false.
     """
     try:
         target_time = os.path.getmtime(target)
     except os.error:
         return 1
     for dep in deps:
         dep_time = os.path.getmtime(dep)
         if dep_time > target_time:
             #print "For target",target,"Dep failed:",dep # dbg
             #print "times (dep,tar):",dep_time,target_time # dbg
             return 1
     return 0
 
 #-----------------------------------------------------------------------------
 def target_update(target,deps,cmd):
     """Update a target with a given command given a list of dependencies.
 
     target_update(target,deps,cmd) -> runs cmd if target is outdated.
 
     This is just a wrapper around target_outdated() which calls the given
     command if target is outdated."""
 
     if target_outdated(target,deps):
         xsys(cmd)
 
 #----------------------------------------------------------------------------
 def unquote_ends(istr):
     """Remove a single pair of quotes from the endpoints of a string."""
 
     if not istr:
         return istr
     if (istr[0]=="'" and istr[-1]=="'") or \
        (istr[0]=='"' and istr[-1]=='"'):
         return istr[1:-1]
     else:
         return istr
 
 #----------------------------------------------------------------------------
 def process_cmdline(argv,names=[],defaults={},usage=''):
     """ Process command-line options and arguments.
 
     Arguments:
 
     - argv: list of arguments, typically sys.argv.
     
     - names: list of option names. See DPyGetOpt docs for details on options
     syntax.
 
     - defaults: dict of default values.
 
     - usage: optional usage notice to print if a wrong argument is passed.
 
     Return a dict of options and a list of free arguments."""
 
     getopt = DPyGetOpt.DPyGetOpt()
     getopt.setIgnoreCase(0)
     getopt.parseConfiguration(names)
 
     try:
         getopt.processArguments(argv)
     except:
         print usage
         warn(`sys.exc_value`,level=4)
 
     defaults.update(getopt.optionValues)
     args = getopt.freeValues
     
     return defaults,args
 
 #----------------------------------------------------------------------------
 def optstr2types(ostr):
     """Convert a string of option names to a dict of type mappings.
 
     optstr2types(str) -> {None:'string_opts',int:'int_opts',float:'float_opts'}
 
     This is used to get the types of all the options in a string formatted
     with the conventions of DPyGetOpt. The 'type' None is used for options
     which are strings (they need no further conversion). This function's main
     use is to get a typemap for use with read_dict().
     """
 
     typeconv = {None:'',int:'',float:''}
     typemap = {'s':None,'i':int,'f':float}
     opt_re = re.compile(r'([\w]*)([^:=]*:?=?)([sif]?)')
 
     for w in ostr.split():
         oname,alias,otype = opt_re.match(w).groups()
         if otype == '' or alias == '!':   # simple switches are integers too
             otype = 'i'
         typeconv[typemap[otype]] += oname + ' '
     return typeconv
 
 #----------------------------------------------------------------------------
 def read_dict(filename,type_conv=None,**opt):
 
     """Read a dictionary of key=value pairs from an input file, optionally
     performing conversions on the resulting values.
 
     read_dict(filename,type_conv,**opt) -> dict
 
     Only one value per line is accepted, the format should be
      # optional comments are ignored
      key value\n
 
     Args:
 
       - type_conv: A dictionary specifying which keys need to be converted to
       which types. By default all keys are read as strings. This dictionary
       should have as its keys valid conversion functions for strings
       (int,long,float,complex, or your own).  The value for each key
       (converter) should be a whitespace separated string containing the names
       of all the entries in the file to be converted using that function. For
       keys to be left alone, use None as the conversion function (only needed
       with purge=1, see below).
 
       - opt: dictionary with extra options as below (default in parens)
 
         purge(0): if set to 1, all keys *not* listed in type_conv are purged out
         of the dictionary to be returned. If purge is going to be used, the
         set of keys to be left as strings also has to be explicitly specified
         using the (non-existent) conversion function None.
 
         fs(None): field separator. This is the key/value separator to be used
         when parsing the file. The None default means any whitespace [behavior
         of string.split()].
 
         strip(0): if 1, strip string values of leading/trailinig whitespace.
 
         warn(1): warning level if requested keys are not found in file.
           - 0: silently ignore.
           - 1: inform but proceed.
           - 2: raise KeyError exception.
 
         no_empty(0): if 1, remove keys with whitespace strings as a value.
 
         unique([]): list of keys (or space separated string) which can't be
         repeated. If one such key is found in the file, each new instance
         overwrites the previous one. For keys not listed here, the behavior is
         to make a list of all appearances.
 
     Example:
     If the input file test.ini has:
       i 3
       x 4.5
       y 5.5
       s hi ho
     Then:
 
     >>> type_conv={int:'i',float:'x',None:'s'}
     >>> read_dict('test.ini')
     {'i': '3', 's': 'hi ho', 'x': '4.5', 'y': '5.5'}
     >>> read_dict('test.ini',type_conv)
     {'i': 3, 's': 'hi ho', 'x': 4.5, 'y': '5.5'}
     >>> read_dict('test.ini',type_conv,purge=1)
     {'i': 3, 's': 'hi ho', 'x': 4.5}
     """
 
     # starting config
     opt.setdefault('purge',0)
     opt.setdefault('fs',None)  # field sep defaults to any whitespace
     opt.setdefault('strip',0)
     opt.setdefault('warn',1)
     opt.setdefault('no_empty',0)
     opt.setdefault('unique','')
     if type(opt['unique']) in StringTypes:
         unique_keys = qw(opt['unique'])
     elif type(opt['unique']) in (types.TupleType,types.ListType):
         unique_keys = opt['unique']
     else:
         raise ValueError, 'Unique keys must be given as a string, List or Tuple'
 
     dict = {}
     # first read in table of values as strings
     file = open(filename,'r')
     for line in file.readlines():
         line = line.strip()
         if len(line) and line[0]=='#': continue
         if len(line)>0:
             lsplit = line.split(opt['fs'],1)
             try:
                 key,val = lsplit
             except ValueError:
                 key,val = lsplit[0],''
             key = key.strip()
             if opt['strip']: val = val.strip()
             if val == "''" or val == '""': val = ''
             if opt['no_empty'] and (val=='' or val.isspace()):
                 continue
             # if a key is found more than once in the file, build a list
             # unless it's in the 'unique' list. In that case, last found in file
             # takes precedence. User beware.
             try:
                 if dict[key] and key in unique_keys:
                     dict[key] = val
                 elif type(dict[key]) is types.ListType:
                     dict[key].append(val)
                 else:
                     dict[key] = [dict[key],val]
             except KeyError:
                 dict[key] = val
     # purge if requested
     if opt['purge']:
         accepted_keys = qwflat(type_conv.values())
         for key in dict.keys():
             if key in accepted_keys: continue
             del(dict[key])
     # now convert if requested
     if type_conv==None: return dict
     conversions = type_conv.keys()
     try: conversions.remove(None)
     except: pass
     for convert in conversions:
         for val in qw(type_conv[convert]):
             try:
                 dict[val] = convert(dict[val])
             except KeyError,e:
                 if opt['warn'] == 0:
                     pass
                 elif opt['warn'] == 1:
                     print >>sys.stderr, 'Warning: key',val,\
                           'not found in file',filename
                 elif opt['warn'] == 2:
                     raise KeyError,e
                 else:
                     raise ValueError,'Warning level must be 0,1 or 2'
 
     return dict
 
 #----------------------------------------------------------------------------
 def flag_calls(func):
     """Wrap a function to detect and flag when it gets called.
 
     This is a decorator which takes a function and wraps it in a function with
     a 'called' attribute. wrapper.called is initialized to False.
 
     The wrapper.called attribute is set to False right before each call to the
     wrapped function, so if the call fails it remains False.  After the call
     completes, wrapper.called is set to True and the output is returned.
 
     Testing for truth in wrapper.called allows you to determine if a call to
     func() was attempted and succeeded."""
     
     def wrapper(*args,**kw):
         wrapper.called = False
         out = func(*args,**kw)
         wrapper.called = True
         return out
 
     wrapper.called = False
     wrapper.__doc__ = func.__doc__
     return wrapper
 
 #----------------------------------------------------------------------------
 class HomeDirError(Error):
     pass
 
 def get_home_dir():
     """Return the closest possible equivalent to a 'home' directory.
 
     We first try $HOME.  Absent that, on NT it's $HOMEDRIVE\$HOMEPATH.
 
     Currently only Posix and NT are implemented, a HomeDirError exception is
     raised for all other OSes. """
 
     isdir = os.path.isdir
     env = os.environ
     try:
         homedir = env['HOME']
         if not isdir(homedir):
             # in case a user stuck some string which does NOT resolve to a
             # valid path, it's as good as if we hadn't foud it
             raise KeyError
         return homedir
     except KeyError:
         if os.name == 'posix':
             raise HomeDirError,'undefined $HOME, IPython can not proceed.'
         elif os.name == 'nt':
             # For some strange reason, win9x returns 'nt' for os.name.
             try:
                 homedir = os.path.join(env['HOMEDRIVE'],env['HOMEPATH'])
                 if not isdir(homedir):
                     homedir = os.path.join(env['USERPROFILE'])
                     if not isdir(homedir):
                         raise HomeDirError
                 return homedir
             except:
                 try:
                     # Use the registry to get the 'My Documents' folder.
                     import _winreg as wreg
                     key = wreg.OpenKey(wreg.HKEY_CURRENT_USER,
                                        "Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders")
                     homedir = wreg.QueryValueEx(key,'Personal')[0]
                     key.Close()
                     if not isdir(homedir):
                         e = ('Invalid "Personal" folder registry key '
                              'typically "My Documents".\n'
                              'Value: %s\n'
                              'This is not a valid directory on your system.' %
                              homedir)
                         raise HomeDirError(e)
                     return homedir
                 except HomeDirError:
                     raise
                 except:
                     return 'C:\\'
         elif os.name == 'dos':
             # Desperate, may do absurd things in classic MacOS. May work under DOS.
             return 'C:\\'
         else:
             raise HomeDirError,'support for your operating system not implemented.'
 
 #****************************************************************************
 # strings and text
 
 class LSString(str):
     """String derivative with a special access attributes.
 
     These are normal strings, but with the special attributes:
 
         .l (or .list) : value as list (split on newlines).
         .n (or .nlstr): original value (the string itself).
         .s (or .spstr): value as whitespace-separated string.
         
     Any values which require transformations are computed only once and
     cached.
 
     Such strings are very useful to efficiently interact with the shell, which
     typically only understands whitespace-separated options for commands."""
 
     def get_list(self):
         try:
             return self.__list
         except AttributeError:
             self.__list = self.split('\n')
             return self.__list
 
     l = list = property(get_list)
 
     def get_spstr(self):
         try:
             return self.__spstr
         except AttributeError:
             self.__spstr = self.replace('\n',' ')
             return self.__spstr
 
     s = spstr = property(get_spstr)
 
     def get_nlstr(self):
         return self
 
     n = nlstr = property(get_nlstr)
 
 class SList(list):
     """List derivative with a special access attributes.
 
     These are normal lists, but with the special attributes:
 
         .l (or .list) : value as list (the list itself).
         .n (or .nlstr): value as a string, joined on newlines.
         .s (or .spstr): value as a string, joined on spaces.
 
     Any values which require transformations are computed only once and
     cached."""
 
     def get_list(self):
         return self
 
     l = list = property(get_list)
 
     def get_spstr(self):
         try:
             return self.__spstr
         except AttributeError:
             self.__spstr = ' '.join(self)
             return self.__spstr
 
     s = spstr = property(get_spstr)
 
     def get_nlstr(self):
         try:
             return self.__nlstr
         except AttributeError:
             self.__nlstr = '\n'.join(self)
             return self.__nlstr
 
     n = nlstr = property(get_nlstr)
 
 def raw_input_multi(header='', ps1='==> ', ps2='..> ',terminate_str = '.'):
     """Take multiple lines of input.
 
     A list with each line of input as a separate element is returned when a
     termination string is entered (defaults to a single '.'). Input can also
     terminate via EOF (^D in Unix, ^Z-RET in Windows).
 
     Lines of input which end in \\ are joined into single entries (and a
     secondary continuation prompt is issued as long as the user terminates
     lines with \\). This allows entering very long strings which are still
     meant to be treated as single entities.
     """
 
     try:
         if header:
             header += '\n'
         lines = [raw_input(header + ps1)]
     except EOFError:
         return []
     terminate = [terminate_str]
     try:
         while lines[-1:] != terminate:
             new_line = raw_input(ps1)
             while new_line.endswith('\\'):
                 new_line = new_line[:-1] + raw_input(ps2)
             lines.append(new_line)
                 
         return lines[:-1]  # don't return the termination command
     except EOFError:
         print
         return lines
 
 #----------------------------------------------------------------------------
 def raw_input_ext(prompt='',  ps2='... '):
     """Similar to raw_input(), but accepts extended lines if input ends with \\."""
 
     line = raw_input(prompt)
     while line.endswith('\\'):
         line = line[:-1] + raw_input(ps2)
     return line
 
 #----------------------------------------------------------------------------
 def ask_yes_no(prompt,default=None):
     """Asks a question and returns an integer 1/0 (y/n) answer.
 
     If default is given (one of 'y','n'), it is used if the user input is
     empty. Otherwise the question is repeated until an answer is given.
     If EOF occurs 20 times consecutively, the default answer is assumed,
     or if there is no default, an exception is raised to prevent infinite
     loops.
 
     Valid answers are: y/yes/n/no (match is not case sensitive)."""
 
     answers = {'y':1,'n':0,'yes':1,'no':0}
     ans = None
     eofs, max_eofs = 0, 20
     while ans not in answers.keys():
         try:
             ans = raw_input(prompt+' ').lower()
             if not ans:  # response was an empty string
                 ans = default
             eofs = 0
         except (EOFError,KeyboardInterrupt):
             eofs = eofs + 1
             if eofs >= max_eofs:
                 if default in answers.keys():
                     ans = default
                 else:
                     raise
             
     return answers[ans]
 
 #----------------------------------------------------------------------------
+def marquee(txt='',width=80,mark='*'):
+    """Return the input string centered in a 'marquee'."""
+    if not txt:
+        return (mark*width)[:width]
+    nmark = (width-len(txt)-2)/len(mark)/2
+    if nmark < 0: nmark =0
+    marks = mark*nmark
+    return '%s %s %s' % (marks,txt,marks)
+
+#----------------------------------------------------------------------------
 class EvalDict:
     """
     Emulate a dict which evaluates its contents in the caller's frame.
 
     Usage:
     >>>number = 19
     >>>text = "python"
     >>>print "%(text.capitalize())s %(number/9.0).1f rules!" % EvalDict()
     """
 
     # This version is due to [e-mail] on c.l.py, and is basically a
     # modified (shorter) version of:
     # http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/66018 by
     # Skip Montanaro ([e-mail]).
 
     def __getitem__(self, name):
         frame = sys._getframe(1)
         return eval(name, frame.f_globals, frame.f_locals)
 
 EvalString = EvalDict  # for backwards compatibility
 #----------------------------------------------------------------------------
 def qw(words,flat=0,sep=None,maxsplit=-1):
     """Similar to Perl's qw() operator, but with some more options.
 
     qw(words,flat=0,sep=' ',maxsplit=-1) -> words.split(sep,maxsplit)
 
     words can also be a list itself, and with flat=1, the output will be
     recursively flattened. Examples:
 
     >>> qw('1 2')
     ['1', '2']
     >>> qw(['a b','1 2',['m n','p q']])
     [['a', 'b'], ['1', '2'], [['m', 'n'], ['p', 'q']]]
     >>> qw(['a b','1 2',['m n','p q']],flat=1)
     ['a', 'b', '1', '2', 'm', 'n', 'p', 'q']    """
 
     if type(words) in StringTypes:
         return [word.strip() for word in words.split(sep,maxsplit)
                 if word and not word.isspace() ]
     if flat:
         return flatten(map(qw,words,[1]*len(words)))
     return map(qw,words)
 
 #----------------------------------------------------------------------------
 def qwflat(words,sep=None,maxsplit=-1):
     """Calls qw(words) in flat mode. It's just a convenient shorthand."""
     return qw(words,1,sep,maxsplit)
 
 #-----------------------------------------------------------------------------
 def list_strings(arg):
     """Always return a list of strings, given a string or list of strings
     as input."""
 
     if type(arg) in StringTypes: return [arg]
     else: return arg
 
 #----------------------------------------------------------------------------
 def grep(pat,list,case=1):
     """Simple minded grep-like function.
     grep(pat,list) returns occurrences of pat in list, None on failure.
 
     It only does simple string matching, with no support for regexps. Use the
     option case=0 for case-insensitive matching."""
 
     # This is pretty crude. At least it should implement copying only references
     # to the original data in case it's big. Now it copies the data for output.
     out=[]
     if case:
         for term in list:
             if term.find(pat)>-1: out.append(term)
     else:
         lpat=pat.lower()
         for term in list:
             if term.lower().find(lpat)>-1: out.append(term)
 
     if len(out): return out
     else: return None
 
 #----------------------------------------------------------------------------
 def dgrep(pat,*opts):
     """Return grep() on dir()+dir(__builtins__).
 
     A very common use of grep() when working interactively."""
 
     return grep(pat,dir(__main__)+dir(__main__.__builtins__),*opts)
 
 #----------------------------------------------------------------------------
 def idgrep(pat):
     """Case-insensitive dgrep()"""
 
     return dgrep(pat,0)
 
 #----------------------------------------------------------------------------
 def igrep(pat,list):
     """Synonym for case-insensitive grep."""
 
     return grep(pat,list,case=0)
 
 #----------------------------------------------------------------------------
 def indent(str,nspaces=4,ntabs=0):
     """Indent a string a given number of spaces or tabstops.
     
     indent(str,nspaces=4,ntabs=0) -> indent str by ntabs+nspaces.
     """
     if str is None:
         return
     ind = '\t'*ntabs+' '*nspaces
     outstr = '%s%s' % (ind,str.replace(os.linesep,os.linesep+ind))
     if outstr.endswith(os.linesep+ind):
         return outstr[:-len(ind)]
     else:
         return outstr
     
 #-----------------------------------------------------------------------------
 def native_line_ends(filename,backup=1):
     """Convert (in-place) a file to line-ends native to the current OS.
 
     If the optional backup argument is given as false, no backup of the
     original file is left.  """
 
     backup_suffixes = {'posix':'~','dos':'.bak','nt':'.bak','mac':'.bak'}
 
     bak_filename = filename + backup_suffixes[os.name]
 
     original = open(filename).read()
     shutil.copy2(filename,bak_filename)
     try:
         new = open(filename,'wb')
         new.write(os.linesep.join(original.splitlines()))
         new.write(os.linesep) # ALWAYS put an eol at the end of the file
         new.close()
     except:
         os.rename(bak_filename,filename)
     if not backup:
         try:
             os.remove(bak_filename)
         except:
             pass
     
 #----------------------------------------------------------------------------
 def get_pager_cmd(pager_cmd = None):
     """Return a pager command.
 
     Makes some attempts at finding an OS-correct one."""
     
     if os.name == 'posix':
         default_pager_cmd = 'less -r'  # -r for color control sequences
     elif os.name in ['nt','dos']:
         default_pager_cmd = 'type'
 
     if pager_cmd is None:
         try:
             pager_cmd = os.environ['PAGER']
         except:
             pager_cmd = default_pager_cmd
     return pager_cmd
 
 #-----------------------------------------------------------------------------
 def get_pager_start(pager,start):
     """Return the string for paging files with an offset.
 
     This is the '+N' argument which less and more (under Unix) accept.
     """
 
     if pager in ['less','more']:
         if start:
             start_string = '+' + str(start)
         else:
             start_string = ''
     else:
         start_string = ''
     return start_string
 
 #----------------------------------------------------------------------------
 def page_dumb(strng,start=0,screen_lines=25):
     """Very dumb 'pager' in Python, for when nothing else works.
 
     Only moves forward, same interface as page(), except for pager_cmd and
     mode."""
 
     out_ln  = strng.splitlines()[start:]
     screens = chop(out_ln,screen_lines-1)
     if len(screens) == 1:
         print >>Term.cout, os.linesep.join(screens[0])
     else:
         for scr in screens[0:-1]:
             print >>Term.cout, os.linesep.join(scr)
             ans = raw_input('---Return to continue, q to quit--- ')
             if ans.lower().startswith('q'):
                 return
         print >>Term.cout, os.linesep.join(screens[-1])
 
 #----------------------------------------------------------------------------
 def page(strng,start=0,screen_lines=0,pager_cmd = None):
     """Print a string, piping through a pager after a certain length.
 
     The screen_lines parameter specifies the number of *usable* lines of your
     terminal screen (total lines minus lines you need to reserve to show other
     information).
 
     If you set screen_lines to a number <=0, page() will try to auto-determine
     your screen size and will only use up to (screen_size+screen_lines) for
     printing, paging after that. That is, if you want auto-detection but need
     to reserve the bottom 3 lines of the screen, use screen_lines = -3, and for
     auto-detection without any lines reserved simply use screen_lines = 0.
 
     If a string won't fit in the allowed lines, it is sent through the
     specified pager command. If none given, look for PAGER in the environment,
     and ultimately default to less.
 
     If no system pager works, the string is sent through a 'dumb pager'
     written in python, very simplistic.
     """
     
     # Ugly kludge, but calling curses.initscr() flat out crashes in emacs
     TERM = os.environ.get('TERM','dumb')
     if TERM in ['dumb','emacs'] and os.name != 'nt':
         print strng
         return
     # chop off the topmost part of the string we don't want to see
     str_lines = strng.split(os.linesep)[start:]
     str_toprint = os.linesep.join(str_lines)
     num_newlines = len(str_lines)
     len_str = len(str_toprint)
     
     # Dumb heuristics to guesstimate number of on-screen lines the string
     # takes.  Very basic, but good enough for docstrings in reasonable
     # terminals. If someone later feels like refining it, it's not hard.
     numlines = max(num_newlines,int(len_str/80)+1)
 
     screen_lines_def = 25 # default value if we can't auto-determine
 
     # auto-determine screen size
     if screen_lines <= 0:
         if TERM=='xterm':
             try:
                 import curses
                 if hasattr(curses,'initscr'):
                     use_curses = 1
                 else:
                     use_curses = 0
             except ImportError:
                 use_curses = 0
         else:
             # curses causes problems on many terminals other than xterm.
             use_curses = 0
         if use_curses:
                 scr = curses.initscr()
                 screen_lines_real,screen_cols = scr.getmaxyx()
                 curses.endwin()
                 screen_lines += screen_lines_real
                 #print '***Screen size:',screen_lines_real,'lines x',\
                 #screen_cols,'columns.' # dbg
         else:
                 screen_lines += screen_lines_def
 
     #print 'numlines',numlines,'screenlines',screen_lines  # dbg
     if numlines <= screen_lines :
         #print '*** normal print'  # dbg
         print >>Term.cout, str_toprint
     else:
         # Try to open pager and default to internal one if that fails.
         # All failure modes are tagged as 'retval=1', to match the return
         # value of a failed system command.  If any intermediate attempt
         # sets retval to 1, at the end we resort to our own page_dumb() pager.
         pager_cmd = get_pager_cmd(pager_cmd)
         pager_cmd += ' ' + get_pager_start(pager_cmd,start)
         if os.name == 'nt':
             if pager_cmd.startswith('type'):
                 # The default WinXP 'type' command is failing on complex strings.
                 retval = 1
             else:
                 tmpname = tempfile.mktemp('.txt')
                 tmpfile = file(tmpname,'wt')
                 tmpfile.write(strng)
                 tmpfile.close()
                 cmd = "%s < %s" % (pager_cmd,tmpname)
                 if os.system(cmd):
                   retval = 1
                 else:
                   retval = None
                 os.remove(tmpname)
         else:
             try:
                 retval = None
                 # if I use popen4, things hang. No idea why.
                 #pager,shell_out = os.popen4(pager_cmd)
                 pager = os.popen(pager_cmd,'w')
                 pager.write(strng)
                 pager.close()
                 retval = pager.close()  # success returns None
             except IOError,msg:  # broken pipe when user quits
                 if msg.args == (32,'Broken pipe'):
                     retval = None
                 else:
                     retval = 1
             except OSError:
                 # Other strange problems, sometimes seen in Win2k/cygwin
                 retval = 1
         if retval is not None:
             page_dumb(strng,screen_lines=screen_lines)
 
 #----------------------------------------------------------------------------
 def page_file(fname,start = 0, pager_cmd = None):
     """Page a file, using an optional pager command and starting line.
     """
 
     pager_cmd = get_pager_cmd(pager_cmd)
     pager_cmd += ' ' + get_pager_start(pager_cmd,start)
 
     try:
         if os.environ['TERM'] in ['emacs','dumb']:
             raise EnvironmentError
         xsys(pager_cmd + ' ' + fname)
     except:
         try:
             if start > 0:
                 start -= 1
             page(open(fname).read(),start)
         except:
             print 'Unable to show file',`fname`
 
 #----------------------------------------------------------------------------
 def snip_print(str,width = 75,print_full = 0,header = ''):
     """Print a string snipping the midsection to fit in width.
 
     print_full: mode control:
       - 0: only snip long strings
       - 1: send to page() directly.
       - 2: snip long strings and ask for full length viewing with page()
     Return 1 if snipping was necessary, 0 otherwise."""
 
     if print_full == 1:
         page(header+str)
         return 0
 
     print header,
     if len(str) < width:
         print str
         snip = 0
     else:
         whalf = int((width -5)/2)
         print str[:whalf] + ' <...> ' + str[-whalf:]
         snip = 1
     if snip and print_full == 2:
         if raw_input(header+' Snipped. View (y/n)? [N]').lower() == 'y':
             page(str)
     return snip
 
 #****************************************************************************
 # lists, dicts and structures
 
 def belong(candidates,checklist):
     """Check whether a list of items appear in a given list of options.
 
     Returns a list of 1 and 0, one for each candidate given."""
 
     return [x in checklist for x in candidates]
 
 #----------------------------------------------------------------------------
 def uniq_stable(elems):
     """uniq_stable(elems) -> list
 
     Return from an iterable, a list of all the unique elements in the input,
     but maintaining the order in which they first appear.
 
     A naive solution to this problem which just makes a dictionary with the
     elements as keys fails to respect the stability condition, since
     dictionaries are unsorted by nature.
 
     Note: All elements in the input must be valid dictionary keys for this
     routine to work, as it internally uses a dictionary for efficiency
     reasons."""
     
     unique = []
     unique_dict = {}
     for nn in elems:
         if nn not in unique_dict:
             unique.append(nn)
             unique_dict[nn] = None
     return unique
 
 #----------------------------------------------------------------------------
 class NLprinter:
     """Print an arbitrarily nested list, indicating index numbers.
 
     An instance of this class called nlprint is available and callable as a
     function.
     
     nlprint(list,indent=' ',sep=': ') -> prints indenting each level by 'indent'
     and using 'sep' to separate the index from the value. """
 
     def __init__(self):
         self.depth = 0
     
     def __call__(self,lst,pos='',**kw):
         """Prints the nested list numbering levels."""
         kw.setdefault('indent',' ')
         kw.setdefault('sep',': ')
         kw.setdefault('start',0)
         kw.setdefault('stop',len(lst))
         # we need to remove start and stop from kw so they don't propagate
         # into a recursive call for a nested list.
         start = kw['start']; del kw['start']
         stop = kw['stop']; del kw['stop']
         if self.depth == 0 and 'header' in kw.keys():
             print kw['header']
             
         for idx in range(start,stop):
             elem = lst[idx]
             if type(elem)==type([]):
                 self.depth += 1
                 self.__call__(elem,itpl('$pos$idx,'),**kw)
                 self.depth -= 1
             else:
                 printpl(kw['indent']*self.depth+'$pos$idx$kw["sep"]$elem')
 
 nlprint = NLprinter()
 #----------------------------------------------------------------------------
 def all_belong(candidates,checklist):
     """Check whether a list of items ALL appear in a given list of options.
 
     Returns a single 1 or 0 value."""
 
     return 1-(0 in [x in checklist for x in candidates])
 
 #----------------------------------------------------------------------------
 def sort_compare(lst1,lst2,inplace = 1):
     """Sort and compare two lists.
 
     By default it does it in place, thus modifying the lists. Use inplace = 0
     to avoid that (at the cost of temporary copy creation)."""
     if not inplace:
         lst1 = lst1[:]
         lst2 = lst2[:]
     lst1.sort(); lst2.sort()
     return lst1 == lst2
 
 #----------------------------------------------------------------------------
 def mkdict(**kwargs):
     """Return a dict from a keyword list.
 
     It's just syntactic sugar for making ditcionary creation more convenient:
     # the standard way
     >>>data = { 'red' : 1, 'green' : 2, 'blue' : 3 }
     # a cleaner way
     >>>data = dict(red=1, green=2, blue=3)
 
     If you need more than this, look at the Struct() class."""
 
     return kwargs
 
 #----------------------------------------------------------------------------
 def list2dict(lst):
     """Takes a list of (key,value) pairs and turns it into a dict."""
 
     dic = {}
     for k,v in lst: dic[k] = v
     return dic
 
 #----------------------------------------------------------------------------
 def list2dict2(lst,default=''):
     """Takes a list and turns it into a dict.
     Much slower than list2dict, but more versatile. This version can take
     lists with sublists of arbitrary length (including sclars)."""
 
     dic = {}
     for elem in lst:
         if type(elem) in (types.ListType,types.TupleType):
             size = len(elem)
             if  size == 0:
                 pass
             elif size == 1:
                 dic[elem] = default
             else:
                 k,v = elem[0], elem[1:]
                 if len(v) == 1: v = v[0]
                 dic[k] = v
         else:
             dic[elem] = default
     return dic
 
 #----------------------------------------------------------------------------
 def flatten(seq):
     """Flatten a list of lists (NOT recursive, only works for 2d lists)."""
 
     # bug in python??? (YES. Fixed in 2.2, let's leave the kludgy fix in).
 
     # if the x=0 isn't made, a *global* variable x is left over after calling
     # this function, with the value of the last element in the return
     # list. This does seem like a bug big time to me.
 
     # the problem is fixed with the x=0, which seems to force the creation of
     # a local name
 
     x = 0 
     return [x for subseq in seq for x in subseq]
 
 #----------------------------------------------------------------------------
 def get_slice(seq,start=0,stop=None,step=1):
     """Get a slice of a sequence with variable step. Specify start,stop,step."""
     if stop == None:
         stop = len(seq)
     item = lambda i: seq[i]
     return map(item,xrange(start,stop,step))
 
 #----------------------------------------------------------------------------
 def chop(seq,size):
     """Chop a sequence into chunks of the given size."""
     chunk = lambda i: seq[i:i+size]
     return map(chunk,xrange(0,len(seq),size))
 
 #----------------------------------------------------------------------------
 def with(object, **args):
     """Set multiple attributes for an object, similar to Pascal's with.
 
     Example:
     with(jim,
          born = 1960,
          haircolour = 'Brown',
          eyecolour = 'Green')
 
     Credit: Greg Ewing, in
     http://mail.python.org/pipermail/python-list/2001-May/040703.html"""
 
     object.__dict__.update(args)
 
 #----------------------------------------------------------------------------
 def setattr_list(obj,alist,nspace = None):
     """Set a list of attributes for an object taken from a namespace.
 
     setattr_list(obj,alist,nspace) -> sets in obj all the attributes listed in
     alist with their values taken from nspace, which must be a dict (something
     like locals() will often do) If nspace isn't given, locals() of the
     *caller* is used, so in most cases you can omit it.
 
     Note that alist can be given as a string, which will be automatically
     split into a list on whitespace. If given as a list, it must be a list of
     *strings* (the variable names themselves), not of variables."""
 
     # this grabs the local variables from the *previous* call frame -- that is
     # the locals from the function that called setattr_list().
     # - snipped from weave.inline()
     if nspace is None:
         call_frame = sys._getframe().f_back
         nspace = call_frame.f_locals
 
     if type(alist) in StringTypes:
         alist = alist.split()
     for attr in alist:
         val = eval(attr,nspace)
         setattr(obj,attr,val)
 
 #----------------------------------------------------------------------------
 def getattr_list(obj,alist,*args):
     """getattr_list(obj,alist[, default]) -> attribute list.
 
     Get a list of named attributes for an object. When a default argument is
     given, it is returned when the attribute doesn't exist; without it, an
     exception is raised in that case.
 
     Note that alist can be given as a string, which will be automatically
     split into a list on whitespace. If given as a list, it must be a list of
     *strings* (the variable names themselves), not of variables."""
 
     if type(alist) in StringTypes:
         alist = alist.split()
     if args:
         if len(args)==1:
             default = args[0]
             return map(lambda attr: getattr(obj,attr,default),alist)
         else:
             raise ValueError,'getattr_list() takes only one optional argument'
     else:
         return map(lambda attr: getattr(obj,attr),alist)
     
 #----------------------------------------------------------------------------
 def map_method(method,object_list,*argseq,**kw):
     """map_method(method,object_list,*args,**kw) -> list
 
     Return a list of the results of applying the methods to the items of the
     argument sequence(s).  If more than one sequence is given, the method is
     called with an argument list consisting of the corresponding item of each
     sequence. All sequences must be of the same length.
 
     Keyword arguments are passed verbatim to all objects called.
 
     This is Python code, so it's not nearly as fast as the builtin map()."""
 
     out_list = []
     idx = 0
     for object in object_list:
         try:
             handler = getattr(object, method)
         except AttributeError:
             out_list.append(None)
         else:
             if argseq:
                 args = map(lambda lst:lst[idx],argseq)
                 #print 'ob',object,'hand',handler,'ar',args # dbg
                 out_list.append(handler(args,**kw))
             else:
                 out_list.append(handler(**kw))
         idx += 1
     return out_list
 
 #----------------------------------------------------------------------------
 # Proposed popitem() extension, written as a method
 
 class NotGiven: pass
 
 def popkey(dct,key,default=NotGiven):
     """Return dct[key] and delete dct[key].
 
     If default is given, return it if dct[key] doesn't exist, otherwise raise
     KeyError.  """
 
     try:
         val = dct[key]
     except KeyError:
         if default is NotGiven:
             raise
         else:
             return default
     else:
         del dct[key]
         return val
 #*************************** end of file <genutils.py> **********************
 

IPython/iplib.py

@@ -1,2047 +1,2047 b''
 # -*- coding: utf-8 -*-
 """
 IPython -- An enhanced Interactive Python
 
 Requires Python 2.1 or newer.
 
 This file contains all the classes and helper functions specific to IPython.
 
-$Id: iplib.py 874 2005-09-20 20:13:04Z fperez $
+$Id: iplib.py 894 2005-09-22 07:16:18Z fperez $
 """
 
 #*****************************************************************************
 #       Copyright (C) 2001 Janko Hauser <[e-mail]> and
 #       Copyright (C) 2001-2004 Fernando Perez. <[e-mail]>
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #
 # Note: this code originally subclassed code.InteractiveConsole from the
 # Python standard library.  Over time, much of that class has been copied
 # verbatim here for modifications which could not be accomplished by
 # subclassing.  The Python License (sec. 2) allows for this, but it's always
 # nice to acknowledge credit where credit is due.
 #*****************************************************************************
 
 #****************************************************************************
 # Modules and globals
 
 from __future__ import generators  # for 2.2 backwards-compatibility
 
 from IPython import Release
 __author__  = '%s <%s>\n%s <%s>' % \
               ( Release.authors['Janko'] + Release.authors['Fernando'] )
 __license__ = Release.license
 __version__ = Release.version
 
 # Python standard modules
 import __main__
 import __builtin__
 import exceptions
 import keyword
 import new
 import os, sys, shutil
 import code, glob, types, re
 import string, StringIO
 import inspect, pydoc
 import bdb, pdb
 import UserList # don't subclass list so this works with Python2.1
 from pprint import pprint, pformat
 import cPickle as pickle
 import traceback
 
 # IPython's own modules
 import IPython
 from IPython import OInspect,PyColorize,ultraTB
 from IPython.ultraTB import ColorScheme,ColorSchemeTable  # too long names
 from IPython.Logger import Logger
 from IPython.Magic import Magic,magic2python,shlex_split
 from IPython.usage import cmd_line_usage,interactive_usage
 from IPython.Struct import Struct
 from IPython.Itpl import Itpl,itpl,printpl,ItplNS,itplns
 from IPython.FakeModule import FakeModule
 from IPython.background_jobs import BackgroundJobManager
 from IPython.genutils import *
 
 # Global pointer to the running 
 
 # store the builtin raw_input globally, and use this always, in case user code
 # overwrites it (like wx.py.PyShell does)
 raw_input_original = raw_input
 
 #****************************************************************************
 # Some utility function definitions
 
 class Bunch: pass
 
 def esc_quotes(strng):
     """Return the input string with single and double quotes escaped out"""
 
     return strng.replace('"','\\"').replace("'","\\'")
 
 def import_fail_info(mod_name,fns=None):
     """Inform load failure for a module."""
 
     if fns == None:
         warn("Loading of %s failed.\n" % (mod_name,))
     else:
         warn("Loading of %s from %s failed.\n" % (fns,mod_name))
 
 def qw_lol(indata):
     """qw_lol('a b') -> [['a','b']],
     otherwise it's just a call to qw().
 
     We need this to make sure the modules_some keys *always* end up as a
     list of lists."""
 
     if type(indata) in StringTypes:
         return [qw(indata)]
     else:
         return qw(indata)
 
 def ipmagic(arg_s):
     """Call a magic function by name.
 
     Input: a string containing the name of the magic function to call and any
     additional arguments to be passed to the magic.
 
     ipmagic('name -opt foo bar') is equivalent to typing at the ipython
     prompt:
 
     In[1]: %name -opt foo bar
 
     To call a magic without arguments, simply use ipmagic('name').
 
     This provides a proper Python function to call IPython's magics in any
     valid Python code you can type at the interpreter, including loops and
     compound statements.  It is added by IPython to the Python builtin
     namespace upon initialization."""
 
     args = arg_s.split(' ',1)
     magic_name = args[0]
     if magic_name.startswith(__IPYTHON__.ESC_MAGIC):
         magic_name = magic_name[1:]
     try:
         magic_args = args[1]
     except IndexError:
         magic_args = ''
     fn = getattr(__IPYTHON__,'magic_'+magic_name,None)
     if fn is None:
         error("Magic function `%s` not found." % magic_name)
     else:
         magic_args = __IPYTHON__.var_expand(magic_args)
         return fn(magic_args)
 
 def ipalias(arg_s):
     """Call an alias by name.
 
     Input: a string containing the name of the alias to call and any
     additional arguments to be passed to the magic.
 
     ipalias('name -opt foo bar') is equivalent to typing at the ipython
     prompt:
 
     In[1]: name -opt foo bar
 
     To call an alias without arguments, simply use ipalias('name').
 
     This provides a proper Python function to call IPython's aliases in any
     valid Python code you can type at the interpreter, including loops and
     compound statements.  It is added by IPython to the Python builtin
     namespace upon initialization."""
 
     args = arg_s.split(' ',1)
     alias_name = args[0]
     try:
         alias_args = args[1]
     except IndexError:
         alias_args = ''
     if alias_name in __IPYTHON__.alias_table:
         __IPYTHON__.call_alias(alias_name,alias_args)
     else:
         error("Alias `%s` not found." % alias_name)
 
 #-----------------------------------------------------------------------------
 # Local use classes
 try:
     from IPython import FlexCompleter
 
     class MagicCompleter(FlexCompleter.Completer):
         """Extension of the completer class to work on %-prefixed lines."""
 
         def __init__(self,shell,namespace=None,omit__names=0,alias_table=None):
             """MagicCompleter() -> completer
 
             Return a completer object suitable for use by the readline library
             via readline.set_completer().
 
             Inputs:
 
             - shell: a pointer to the ipython shell itself.  This is needed
             because this completer knows about magic functions, and those can
             only be accessed via the ipython instance.
 
             - namespace: an optional dict where completions are performed.
             
             - The optional omit__names parameter sets the completer to omit the
             'magic' names (__magicname__) for python objects unless the text
             to be completed explicitly starts with one or more underscores.
 
             - If alias_table is supplied, it should be a dictionary of aliases
             to complete. """
 
             FlexCompleter.Completer.__init__(self,namespace)
             self.magic_prefix = shell.name+'.magic_'
             self.magic_escape = shell.ESC_MAGIC
             self.readline = FlexCompleter.readline
             delims = self.readline.get_completer_delims()
             delims = delims.replace(self.magic_escape,'')
             self.readline.set_completer_delims(delims)
             self.get_line_buffer = self.readline.get_line_buffer
             self.omit__names = omit__names
             self.merge_completions = shell.rc.readline_merge_completions
             
             if alias_table is None:
                 alias_table = {}
             self.alias_table = alias_table
             # Regexp to split filenames with spaces in them
             self.space_name_re = re.compile(r'([^\\] )')
             # Hold a local ref. to glob.glob for speed
             self.glob = glob.glob
             # Special handling of backslashes needed in win32 platforms
             if sys.platform == "win32":
                 self.clean_glob = self._clean_glob_win32
             else:
                 self.clean_glob = self._clean_glob
             self.matchers = [self.python_matches,
                              self.file_matches,
                              self.alias_matches,
                              self.python_func_kw_matches]
 
         # Code contributed by Alex Schmolck, for ipython/emacs integration
         def all_completions(self, text):
             """Return all possible completions for the benefit of emacs."""
             
             completions = []
             try:
                 for i in xrange(sys.maxint):
                     res = self.complete(text, i)
 
                     if not res: break
 
                     completions.append(res)
             #XXX workaround for ``notDefined.<tab>``
             except NameError:
                 pass
             return completions
         # /end Alex Schmolck code.
 
         def _clean_glob(self,text):
             return self.glob("%s*" % text)
             
         def _clean_glob_win32(self,text):
             return [f.replace("\\","/")
                     for f in self.glob("%s*" % text)]            
 
         def file_matches(self, text):
             """Match filneames, expanding ~USER type strings.
 
             Most of the seemingly convoluted logic in this completer is an
             attempt to handle filenames with spaces in them.  And yet it's not
             quite perfect, because Python's readline doesn't expose all of the
             GNU readline details needed for this to be done correctly.
 
             For a filename with a space in it, the printed completions will be
             only the parts after what's already been typed (instead of the
             full completions, as is normally done).  I don't think with the
             current (as of Python 2.3) Python readline it's possible to do
             better."""
             
             #print 'Completer->file_matches: <%s>' % text # dbg
 
             # chars that require escaping with backslash - i.e. chars
             # that readline treats incorrectly as delimiters, but we
             # don't want to treat as delimiters in filename matching
             # when escaped with backslash
             
             protectables = ' ()[]{}'
 
             def protect_filename(s):
                 return "".join([(ch in protectables and '\\' + ch or ch)
                                 for ch in s])
 
             lbuf = self.get_line_buffer()[:self.readline.get_endidx()]
             open_quotes = 0  # track strings with open quotes
             try:
                 lsplit = shlex_split(lbuf)[-1]
             except ValueError:
                 # typically an unmatched ", or backslash without escaped char.
                 if lbuf.count('"')==1:
                     open_quotes = 1
                     lsplit = lbuf.split('"')[-1]
                 elif lbuf.count("'")==1:
                     open_quotes = 1
                     lsplit = lbuf.split("'")[-1]
                 else:
                     return None
             except IndexError:
                 # tab pressed on empty line
                 lsplit = ""
 
             if lsplit != protect_filename(lsplit):
                 # if protectables are found, do matching on the whole escaped
                 # name
                 has_protectables = 1
                 text0,text = text,lsplit
             else:
                 has_protectables = 0
                 text = os.path.expanduser(text)
             
             if text == "":
                 return [protect_filename(f) for f in self.glob("*")]
 
             m0 = self.clean_glob(text.replace('\\',''))
             if has_protectables:
                 # If we had protectables, we need to revert our changes to the
                 # beginning of filename so that we don't double-write the part
                 # of the filename we have so far
                 len_lsplit = len(lsplit)
                 matches = [text0 + protect_filename(f[len_lsplit:]) for f in m0]
             else:
                 if open_quotes:
                     # if we have a string with an open quote, we don't need to
                     # protect the names at all (and we _shouldn't_, as it
                     # would cause bugs when the filesystem call is made).
                     matches = m0
                 else:
                     matches = [protect_filename(f) for f in m0]
             if len(matches) == 1 and os.path.isdir(matches[0]):
                 # Takes care of links to directories also.  Use '/'
                 # explicitly, even under Windows, so that name completions
                 # don't end up escaped.
                 matches[0] += '/'
             return matches
 
         def alias_matches(self, text):
             """Match internal system aliases"""
             #print 'Completer->alias_matches:',text # dbg
             text = os.path.expanduser(text)
             aliases =  self.alias_table.keys()
             if text == "":
                 return aliases
             else:
                 return [alias for alias in aliases if alias.startswith(text)]
             
         def python_matches(self,text):
             """Match attributes or global python names"""
             #print 'Completer->python_matches' # dbg
             if "." in text:
                 try:
                     matches = self.attr_matches(text)
                     if text.endswith('.') and self.omit__names:
                         if self.omit__names == 1:
                             # true if txt is _not_ a __ name, false otherwise:
                             no__name = (lambda txt:
                                         re.match(r'.*\.__.*?__',txt) is None)
                         else:
                             # true if txt is _not_ a _ name, false otherwise:
                             no__name = (lambda txt:
                                         re.match(r'.*\._.*?',txt) is None)
                         matches = filter(no__name, matches)
                 except NameError:
                     # catches <undefined attributes>.<tab>
                     matches = []
             else:
                 matches = self.global_matches(text)
                 # this is so completion finds magics when automagic is on:
                 if matches == [] and not text.startswith(os.sep):
                     matches = self.attr_matches(self.magic_prefix+text)
             return matches
 
         def _default_arguments(self, obj):
             """Return the list of default arguments of obj if it is callable,
             or empty list otherwise."""
             
             if not (inspect.isfunction(obj) or inspect.ismethod(obj)):
                 # for classes, check for __init__,__new__
                 if inspect.isclass(obj):
                     obj = (getattr(obj,'__init__',None) or
                            getattr(obj,'__new__',None))
                 # for all others, check if they are __call__able
                 elif hasattr(obj, '__call__'):
                     obj = obj.__call__
                 # XXX: is there a way to handle the builtins ?
             try:
                 args,_,_1,defaults = inspect.getargspec(obj)
                 if defaults:
                     return args[-len(defaults):]
             except TypeError: pass
             return []
 
         def python_func_kw_matches(self,text):
             """Match named parameters (kwargs) of the last open function"""
 
             if "." in text: # a parameter cannot be dotted
                 return []
             try: regexp = self.__funcParamsRegex
             except AttributeError:
                 regexp = self.__funcParamsRegex = re.compile(r'''
                     '.*?' |    # single quoted strings or
                     ".*?" |    # double quoted strings or
                     \w+   |    # identifier
                     \S         # other characters
                     ''', re.VERBOSE | re.DOTALL)
             # 1. find the nearest identifier that comes before an unclosed
             # parenthesis e.g. for "foo (1+bar(x), pa", the candidate is "foo"
             tokens = regexp.findall(self.get_line_buffer())
             tokens.reverse()
             iterTokens = iter(tokens); openPar = 0
             for token in iterTokens:
                 if token == ')':
                     openPar -= 1
                 elif token == '(':
                     openPar += 1
                     if openPar > 0:
                         # found the last unclosed parenthesis
                         break
             else:
                 return []
             # 2. Concatenate any dotted names (e.g. "foo.bar" for "foo.bar(x, pa" )
             ids = []
             isId = re.compile(r'\w+$').match
             while True:
                 try:
                     ids.append(iterTokens.next())
                     if not isId(ids[-1]):
                         ids.pop(); break
                     if not iterTokens.next() == '.':
                         break
                 except StopIteration:
                     break
             # lookup the candidate callable matches either using global_matches
             # or attr_matches for dotted names
             if len(ids) == 1:
                 callableMatches = self.global_matches(ids[0])
             else:
                 callableMatches = self.attr_matches('.'.join(ids[::-1]))
             argMatches = []
             for callableMatch in callableMatches:
                 try: namedArgs = self._default_arguments(eval(callableMatch,
                                                              self.namespace))
                 except: continue
                 for namedArg in namedArgs:
                     if namedArg.startswith(text):
                         argMatches.append("%s=" %namedArg)
             return argMatches
 
         def complete(self, text, state):
             """Return the next possible completion for 'text'.
 
             This is called successively with state == 0, 1, 2, ... until it
             returns None.  The completion should begin with 'text'.  """
             
             #print '\n*** COMPLETE: <%s> (%s)' % (text,state)  # dbg
             magic_escape = self.magic_escape
             magic_prefix = self.magic_prefix
             
             try:
                 if text.startswith(magic_escape):
                     text = text.replace(magic_escape,magic_prefix)
                 elif text.startswith('~'):
                     text = os.path.expanduser(text)
                 if state == 0:
                     # Extend the list of completions with the results of each
                     # matcher, so we return results to the user from all
                     # namespaces.
                     if self.merge_completions:
                         self.matches = []
                         for matcher in self.matchers:
                             self.matches.extend(matcher(text))
                     else:
                         for matcher in self.matchers:
                             self.matches = matcher(text)
                             if self.matches:
                                 break
                         
                 try:
                     return self.matches[state].replace(magic_prefix,magic_escape)
                 except IndexError:
                     return None
             except:
                 # If completion fails, don't annoy the user.
                 pass
 
 except ImportError:
     pass  # no readline support
 
 except KeyError:
     pass  # Windows doesn't set TERM, it doesn't matter
 
 
 class InputList(UserList.UserList):
     """Class to store user input.
 
     It's basically a list, but slices return a string instead of a list, thus
     allowing things like (assuming 'In' is an instance):
 
     exec In[4:7]
 
     or
 
     exec In[5:9] + In[14] + In[21:25]"""
 
     def __getslice__(self,i,j):
         return ''.join(UserList.UserList.__getslice__(self,i,j))
 
 #****************************************************************************
 # Local use exceptions
 class SpaceInInput(exceptions.Exception):
     pass
 
 #****************************************************************************
 # Main IPython class
 
 class InteractiveShell(code.InteractiveConsole, Logger, Magic):
     """An enhanced console for Python."""
 
     def __init__(self,name,usage=None,rc=Struct(opts=None,args=None),
                  user_ns = None,banner2='',
                  custom_exceptions=((),None)):
 
         # Put a reference to self in builtins so that any form of embedded or
         # imported code can test for being inside IPython.
         __builtin__.__IPYTHON__ = self
 
         # And load into builtins ipmagic/ipalias as well
         __builtin__.ipmagic = ipmagic
         __builtin__.ipalias = ipalias
 
         # Add to __builtin__ other parts of IPython's public API
         __builtin__.ip_set_hook = self.set_hook
 
         # Keep in the builtins a flag for when IPython is active.  We set it
         # with setdefault so that multiple nested IPythons don't clobber one
         # another.  Each will increase its value by one upon being activated,
         # which also gives us a way to determine the nesting level.
         __builtin__.__dict__.setdefault('__IPYTHON__active',0)
 
         # Inform the user of ipython's fast exit magics.
         _exit = ' Use %Exit or %Quit to exit without confirmation.'
         __builtin__.exit += _exit
         __builtin__.quit += _exit
 
         # Create the namespace where the user will operate:
 
         # FIXME. For some strange reason, __builtins__ is showing up at user
         # level as a dict instead of a module. This is a manual fix, but I
         # should really track down where the problem is coming from. Alex
         # Schmolck reported this problem first.
 
         # A useful post by Alex Martelli on this topic:
         # Re: inconsistent value from __builtins__
         # Von: Alex Martelli <[e-mail]>
         # Datum: Freitag 01 Oktober 2004 04:45:34 nachmittags/abends
         # Gruppen: comp.lang.python
         # Referenzen: 1
 
         # Michael Hohn <[e-mail]> wrote:
         # > >>> print type(builtin_check.get_global_binding('__builtins__'))
         # > <type 'dict'>
         # > >>> print type(__builtins__)
         # > <type 'module'>
         # > Is this difference in return value intentional?
 
         # Well, it's documented that '__builtins__' can be either a dictionary
         # or a module, and it's been that way for a long time. Whether it's
         # intentional (or sensible), I don't know. In any case, the idea is that
         # if you need to access the built-in namespace directly, you should start
         # with "import __builtin__" (note, no 's') which will definitely give you
         # a module. Yeah, it's somewhat confusing:-(.
         
         if user_ns is None:
             # Set __name__ to __main__ to better match the behavior of the
             # normal interpreter.
             self.user_ns = {'__name__'     :'__main__',
                             '__builtins__' : __builtin__,
                             }
         else:
             self.user_ns = user_ns
 
         # The user namespace MUST have a pointer to the shell itself.
         self.user_ns[name] = self
 
         # We need to insert into sys.modules something that looks like a
         # module but which accesses the IPython namespace, for shelve and
         # pickle to work interactively. Normally they rely on getting
         # everything out of __main__, but for embedding purposes each IPython
         # instance has its own private namespace, so we can't go shoving
         # everything into __main__.
 
         try:
             main_name = self.user_ns['__name__']
         except KeyError:
             raise KeyError,'user_ns dictionary MUST have a "__name__" key'
         else:
             #print "pickle hack in place"  # dbg
             sys.modules[main_name] = FakeModule(self.user_ns)
 
         # List of input with multi-line handling.
         # Fill its zero entry, user counter starts at 1
         self.input_hist = InputList(['\n'])
 
         # list of visited directories
         try:
             self.dir_hist = [os.getcwd()]
         except IOError, e:
             self.dir_hist = []
 
         # dict of output history
         self.output_hist = {}
 
         # dict of names to be treated as system aliases.  Each entry in the
         # alias table must be a 2-tuple of the form (N,name), where N is the
         # number of positional arguments of the alias.
         self.alias_table = {}
 
         # dict of things NOT to alias (keywords, builtins and some special magics)
         no_alias = {}
         no_alias_magics = ['cd','popd','pushd','dhist','alias','unalias']
         for key in keyword.kwlist + no_alias_magics:
             no_alias[key] = 1
         no_alias.update(__builtin__.__dict__)
         self.no_alias = no_alias
         
         
         # make global variables for user access to these
         self.user_ns['_ih'] = self.input_hist
         self.user_ns['_oh'] = self.output_hist
         self.user_ns['_dh'] = self.dir_hist
 
         # user aliases to input and output histories
         self.user_ns['In']  = self.input_hist
         self.user_ns['Out'] = self.output_hist
 
         # Store the actual shell's name
         self.name = name
 
         # Object variable to store code object waiting execution.  This is
         # used mainly by the multithreaded shells, but it can come in handy in
         # other situations.  No need to use a Queue here, since it's a single
         # item which gets cleared once run.
         self.code_to_run = None
         
         # Job manager (for jobs run as background threads)
         self.jobs = BackgroundJobManager()
         # Put the job manager into builtins so it's always there.
         __builtin__.jobs = self.jobs
 
         # escapes for automatic behavior on the command line
         self.ESC_SHELL = '!'
         self.ESC_HELP  = '?'
         self.ESC_MAGIC = '%'
         self.ESC_QUOTE = ','
         self.ESC_QUOTE2 = ';'
         self.ESC_PAREN = '/'
 
         # And their associated handlers
         self.esc_handlers = {self.ESC_PAREN:self.handle_auto,
                              self.ESC_QUOTE:self.handle_auto,
                              self.ESC_QUOTE2:self.handle_auto,
                              self.ESC_MAGIC:self.handle_magic,
                              self.ESC_HELP:self.handle_help,
                              self.ESC_SHELL:self.handle_shell_escape,
                              }
 
         # class initializations
         code.InteractiveConsole.__init__(self,locals = self.user_ns)
         Logger.__init__(self,log_ns = self.user_ns)
         Magic.__init__(self,self)
 
         # an ugly hack to get a pointer to the shell, so I can start writing
         # magic code via this pointer instead of the current mixin salad.
         Magic.set_shell(self,self)
 
         # hooks holds pointers used for user-side customizations
         self.hooks = Struct()
         
         # Set all default hooks, defined in the IPython.hooks module.
         hooks = IPython.hooks
         for hook_name in hooks.__all__:
             self.set_hook(hook_name,getattr(hooks,hook_name))
 
         # Flag to mark unconditional exit
         self.exit_now = False
 
         self.usage_min =  """\
         An enhanced console for Python.
         Some of its features are:
         - Readline support if the readline library is present.
         - Tab completion in the local namespace.
         - Logging of input, see command-line options.
         - System shell escape via ! , eg !ls.
         - Magic commands, starting with a % (like %ls, %pwd, %cd, etc.)
         - Keeps track of locally defined variables via %who, %whos.
         - Show object information with a ? eg ?x or x? (use ?? for more info).
         """
         if usage: self.usage = usage
         else: self.usage = self.usage_min
 
         # Storage
         self.rc = rc   # This will hold all configuration information
         self.inputcache = []
         self._boundcache = []
         self.pager = 'less'
         # temporary files used for various purposes.  Deleted at exit.
         self.tempfiles = []
 
         # Keep track of readline usage (later set by init_readline)
         self.has_readline = 0
 
         # for pushd/popd management
         try:
             self.home_dir = get_home_dir()
         except HomeDirError,msg:
             fatal(msg)
 
         self.dir_stack = [os.getcwd().replace(self.home_dir,'~')]
 
         # Functions to call the underlying shell.
 
         # utility to expand user variables via Itpl
         self.var_expand = lambda cmd: str(ItplNS(cmd.replace('#','\#'),
                                                  self.user_ns))
         # The first is similar to os.system, but it doesn't return a value,
         # and it allows interpolation of variables in the user's namespace.
         self.system = lambda cmd: shell(self.var_expand(cmd),
                                         header='IPython system call: ',
                                         verbose=self.rc.system_verbose)
         # These are for getoutput and getoutputerror:
         self.getoutput = lambda cmd: \
                          getoutput(self.var_expand(cmd),
                                    header='IPython system call: ',
                                    verbose=self.rc.system_verbose)
         self.getoutputerror = lambda cmd: \
                               getoutputerror(str(ItplNS(cmd.replace('#','\#'),
                                                         self.user_ns)),
                                              header='IPython system call: ',
                                              verbose=self.rc.system_verbose)
  
         # RegExp for splitting line contents into pre-char//first
         # word-method//rest.  For clarity, each group in on one line.
 
         # WARNING: update the regexp if the above escapes are changed, as they
         # are hardwired in.
 
         # Don't get carried away with trying to make the autocalling catch too
         # much:  it's better to be conservative rather than to trigger hidden
         # evals() somewhere and end up causing side effects.
 
         self.line_split = re.compile(r'^([\s*,;/])'
                                      r'([\?\w\.]+\w*\s*)'
                                      r'(\(?.*$)')
 
         # Original re, keep around for a while in case changes break something
         #self.line_split = re.compile(r'(^[\s*!\?%,/]?)'
         #                             r'(\s*[\?\w\.]+\w*\s*)'
         #                             r'(\(?.*$)')
 
         # RegExp to identify potential function names
         self.re_fun_name = re.compile(r'[a-zA-Z_]([a-zA-Z0-9_.]*) *$')
         # RegExp to exclude strings with this start from autocalling
         self.re_exclude_auto = re.compile('^[!=()<>,\*/\+-]|^is ')
         # try to catch also methods for stuff in lists/tuples/dicts: off
         # (experimental). For this to work, the line_split regexp would need
         # to be modified so it wouldn't break things at '['. That line is
         # nasty enough that I shouldn't change it until I can test it _well_.
         #self.re_fun_name = re.compile (r'[a-zA-Z_]([a-zA-Z0-9_.\[\]]*) ?$')
 
         # keep track of where we started running (mainly for crash post-mortem)
         self.starting_dir = os.getcwd()
 
         # Attributes for Logger mixin class, make defaults here
         self._dolog = 0
         self.LOG = ''
         self.LOGDEF = '.InteractiveShell.log'
         self.LOGMODE = 'over'
         self.LOGHEAD = Itpl(
 """#log# Automatic Logger file. *** THIS MUST BE THE FIRST LINE ***
 #log# DO NOT CHANGE THIS LINE OR THE TWO BELOW
 #log# opts = $self.rc.opts
 #log# args = $self.rc.args
 #log# It is safe to make manual edits below here.
 #log#-----------------------------------------------------------------------
 """)
         # Various switches which can be set
         self.CACHELENGTH = 5000  # this is cheap, it's just text
         self.BANNER = "Python %(version)s on %(platform)s\n" % sys.__dict__
         self.banner2 = banner2
 
         # TraceBack handlers:
         # Need two, one for syntax errors and one for other exceptions.
         self.SyntaxTB = ultraTB.ListTB(color_scheme='NoColor')
         # This one is initialized with an offset, meaning we always want to
         # remove the topmost item in the traceback, which is our own internal
         # code. Valid modes: ['Plain','Context','Verbose']
         self.InteractiveTB = ultraTB.AutoFormattedTB(mode = 'Plain',
                                                      color_scheme='NoColor',
                                                      tb_offset = 1)
         # and add any custom exception handlers the user may have specified
         self.set_custom_exc(*custom_exceptions)
 
         # Object inspector
         ins_colors = OInspect.InspectColors
         code_colors = PyColorize.ANSICodeColors
         self.inspector = OInspect.Inspector(ins_colors,code_colors,'NoColor')
         self.autoindent = 0
 
         # Make some aliases automatically
         # Prepare list of shell aliases to auto-define
         if os.name == 'posix':            
             auto_alias = ('mkdir mkdir', 'rmdir rmdir',
                           'mv mv -i','rm rm -i','cp cp -i',
                           'cat cat','less less','clear clear',
                           # a better ls
                           'ls ls -F',
                           # long ls
                           'll ls -lF',
                           # color ls
                           'lc ls -F -o --color',
                           # ls normal files only
                           'lf ls -F -o --color %l | grep ^-',
                           # ls symbolic links 
                           'lk ls -F -o --color %l | grep ^l',
                           # directories or links to directories,
                           'ldir ls -F -o --color %l | grep /$',
                           # things which are executable
                           'lx ls -F -o --color %l | grep ^-..x',
                           )
         elif os.name in ['nt','dos']:
             auto_alias = ('dir dir /on', 'ls dir /on',
                           'ddir dir /ad /on', 'ldir dir /ad /on',
                           'mkdir mkdir','rmdir rmdir','echo echo',
                           'ren ren','cls cls','copy copy')
         else:
             auto_alias = ()
         self.auto_alias = map(lambda s:s.split(None,1),auto_alias)
         # Call the actual (public) initializer
         self.init_auto_alias()
     # end __init__
 
     def set_hook(self,name,hook):
         """set_hook(name,hook) -> sets an internal IPython hook.
 
         IPython exposes some of its internal API as user-modifiable hooks.  By
         resetting one of these hooks, you can modify IPython's behavior to
         call at runtime your own routines."""
 
         # At some point in the future, this should validate the hook before it
         # accepts it.  Probably at least check that the hook takes the number
         # of args it's supposed to.
         setattr(self.hooks,name,new.instancemethod(hook,self,self.__class__))
 
     def set_custom_exc(self,exc_tuple,handler):
         """set_custom_exc(exc_tuple,handler)
 
         Set a custom exception handler, which will be called if any of the
         exceptions in exc_tuple occur in the mainloop (specifically, in the
         runcode() method.
 
         Inputs:
 
           - exc_tuple: a *tuple* of valid exceptions to call the defined
           handler for.  It is very important that you use a tuple, and NOT A
           LIST here, because of the way Python's except statement works.  If
           you only want to trap a single exception, use a singleton tuple:
 
             exc_tuple == (MyCustomException,)
 
           - handler: this must be defined as a function with the following
           basic interface: def my_handler(self,etype,value,tb).
 
           This will be made into an instance method (via new.instancemethod)
           of IPython itself, and it will be called if any of the exceptions
           listed in the exc_tuple are caught.  If the handler is None, an
           internal basic one is used, which just prints basic info.
 
         WARNING: by putting in your own exception handler into IPython's main
         execution loop, you run a very good chance of nasty crashes.  This
         facility should only be used if you really know what you are doing."""
 
         assert type(exc_tuple)==type(()) , \
                "The custom exceptions must be given AS A TUPLE."
 
         def dummy_handler(self,etype,value,tb):
             print '*** Simple custom exception handler ***'
             print 'Exception type :',etype
             print 'Exception value:',value
             print 'Traceback      :',tb
             print 'Source code    :','\n'.join(self.buffer)
 
         if handler is None: handler = dummy_handler
 
         self.CustomTB = new.instancemethod(handler,self,self.__class__)
         self.custom_exceptions = exc_tuple
 
     def set_custom_completer(self,completer,pos=0):
         """set_custom_completer(completer,pos=0)
 
         Adds a new custom completer function.
 
         The position argument (defaults to 0) is the index in the completers
         list where you want the completer to be inserted."""
 
         newcomp = new.instancemethod(completer,self.Completer,
                                      self.Completer.__class__)
         self.Completer.matchers.insert(pos,newcomp)
 
     def complete(self,text):
         """Return a sorted list of all possible completions on text.
 
         Inputs:
 
           - text: a string of text to be completed on.
 
         This is a wrapper around the completion mechanism, similar to what
         readline does at the command line when the TAB key is hit.  By
         exposing it as a method, it can be used by other non-readline
         environments (such as GUIs) for text completion.
 
         Simple usage example:
 
         In [1]: x = 'hello'
 
         In [2]: __IP.complete('x.l')
         Out[2]: ['x.ljust', 'x.lower', 'x.lstrip']"""
         
         complete = self.Completer.complete
         state = 0
         # use a dict so we get unique keys, since ipyhton's multiple
         # completers can return duplicates.
         comps = {}
         while True:
             newcomp = complete(text,state)
             if newcomp is None:
                 break
             comps[newcomp] = 1
             state += 1
         outcomps = comps.keys()
         outcomps.sort()
         return outcomps
 
     def post_config_initialization(self):
         """Post configuration init method
 
         This is called after the configuration files have been processed to
         'finalize' the initialization."""
         
         # dynamic data that survives through sessions
         # XXX make the filename a config option?
         persist_base = 'persist'
         if self.rc.profile:
             persist_base += '_%s' % self.rc.profile
         self.persist_fname =  os.path.join(self.rc.ipythondir,persist_base)
 
         try:
             self.persist = pickle.load(file(self.persist_fname))
         except:
             self.persist = {}
             
     def init_auto_alias(self):
         """Define some aliases automatically.
 
         These are ALL parameter-less aliases"""
         for alias,cmd in self.auto_alias:
             self.alias_table[alias] = (0,cmd)
 
     def alias_table_validate(self,verbose=0):
         """Update information about the alias table.
 
         In particular, make sure no Python keywords/builtins are in it."""
 
         no_alias = self.no_alias
         for k in self.alias_table.keys():
             if k in no_alias:
                 del self.alias_table[k]
                 if verbose:
                     print ("Deleting alias <%s>, it's a Python "
                            "keyword or builtin." % k)
     
     def set_autoindent(self,value=None):
         """Set the autoindent flag, checking for readline support.
 
         If called with no arguments, it acts as a toggle."""
 
         if not self.has_readline:
             if os.name == 'posix':
                 warn("The auto-indent feature requires the readline library")
             self.autoindent = 0
             return
         if value is None:
             self.autoindent = not self.autoindent
         else:
             self.autoindent = value
 
     def rc_set_toggle(self,rc_field,value=None):
         """Set or toggle a field in IPython's rc config. structure.
 
         If called with no arguments, it acts as a toggle.
 
         If called with a non-existent field, the resulting AttributeError
         exception will propagate out."""
 
         rc_val = getattr(self.rc,rc_field)
         if value is None:
             value = not rc_val
         setattr(self.rc,rc_field,value)
 
     def user_setup(self,ipythondir,rc_suffix,mode='install'):
         """Install the user configuration directory.
 
         Can be called when running for the first time or to upgrade the user's
         .ipython/ directory with the mode parameter. Valid modes are 'install'
         and 'upgrade'."""
 
         def wait():
             try:
                 raw_input("Please press <RETURN> to start IPython.")
             except EOFError:
                 print >> Term.cout
             print '*'*70
 
         cwd = os.getcwd()  # remember where we started
         glb = glob.glob
         print '*'*70
         if mode == 'install':
             print \
 """Welcome to IPython. I will try to create a personal configuration directory
 where you can customize many aspects of IPython's functionality in:\n"""
         else:
             print 'I am going to upgrade your configuration in:'
 
         print ipythondir
 
         rcdirend = os.path.join('IPython','UserConfig')
         cfg = lambda d: os.path.join(d,rcdirend)
         try:
             rcdir = filter(os.path.isdir,map(cfg,sys.path))[0]
         except IOError:
             warning = """
 Installation error. IPython's directory was not found.
 
 Check the following:
 
 The ipython/IPython directory should be in a directory belonging to your
 PYTHONPATH environment variable (that is, it should be in a directory
 belonging to sys.path). You can copy it explicitly there or just link to it.
 
 IPython will proceed with builtin defaults.
 """
             warn(warning)
             wait()
             return
 
         if mode == 'install':
             try:
                 shutil.copytree(rcdir,ipythondir)
                 os.chdir(ipythondir)
                 rc_files = glb("ipythonrc*")
                 for rc_file in rc_files:
                     os.rename(rc_file,rc_file+rc_suffix)
             except:
                 warning = """
 
 There was a problem with the installation:
 %s
 Try to correct it or contact the developers if you think it's a bug.
 IPython will proceed with builtin defaults.""" % sys.exc_info()[1]
                 warn(warning)
                 wait()
                 return
 
         elif mode == 'upgrade':
             try:
                 os.chdir(ipythondir)
             except:
                 print """
 Can not upgrade: changing to directory %s failed. Details:
 %s
 """ % (ipythondir,sys.exc_info()[1])
                 wait()
                 return
             else:
                 sources = glb(os.path.join(rcdir,'[A-Za-z]*'))
                 for new_full_path in sources:
                     new_filename = os.path.basename(new_full_path)
                     if new_filename.startswith('ipythonrc'):
                         new_filename = new_filename + rc_suffix
                     # The config directory should only contain files, skip any
                     # directories which may be there (like CVS)
                     if os.path.isdir(new_full_path):
                         continue
                     if os.path.exists(new_filename):
                         old_file = new_filename+'.old'
                         if os.path.exists(old_file):
                             os.remove(old_file)
                         os.rename(new_filename,old_file)
                     shutil.copy(new_full_path,new_filename)
         else:
             raise ValueError,'unrecognized mode for install:',`mode`
 
         # Fix line-endings to those native to each platform in the config
         # directory.
         try:
             os.chdir(ipythondir)
         except:
             print """
 Problem: changing to directory %s failed.
 Details:
 %s
 
 Some configuration files may have incorrect line endings.  This should not
 cause any problems during execution.  """ % (ipythondir,sys.exc_info()[1])
             wait()
         else:
             for fname in glb('ipythonrc*'):
                 try:
                     native_line_ends(fname,backup=0)
                 except IOError:
                     pass
 
         if mode == 'install':
             print """
 Successful installation!
 
 Please read the sections 'Initial Configuration' and 'Quick Tips' in the
 IPython manual (there are both HTML and PDF versions supplied with the
 distribution) to make sure that your system environment is properly configured
 to take advantage of IPython's features."""
         else:
             print """
 Successful upgrade!
 
 All files in your directory:
 %(ipythondir)s
 which would have been overwritten by the upgrade were backed up with a .old
 extension.  If you had made particular customizations in those files you may
 want to merge them back into the new files.""" % locals()
         wait()
         os.chdir(cwd)
         # end user_setup()
 
     def atexit_operations(self):
         """This will be executed at the time of exit.
 
         Saving of persistent data should be performed here. """
 
         # input history
         self.savehist()
 
         # Cleanup all tempfiles left around
         for tfile in self.tempfiles:
             try:
                 os.unlink(tfile)
             except OSError:
                 pass
 
         # save the "persistent data" catch-all dictionary
         try:
             pickle.dump(self.persist, open(self.persist_fname,"w"))
         except:
             print "*** ERROR *** persistent data saving failed."
         
     def savehist(self):
         """Save input history to a file (via readline library)."""
         try:
             self.readline.write_history_file(self.histfile)
         except:
             print 'Unable to save IPython command history to file: ' + \
                   `self.histfile`
 
     def pre_readline(self):
         """readline hook to be used at the start of each line.
 
         Currently it handles auto-indent only."""
         
         self.readline.insert_text(' '* self.readline_indent)
 
     def init_readline(self):
         """Command history completion/saving/reloading."""
         try:
             import readline
             self.Completer = MagicCompleter(self,
                                             self.user_ns,
                                             self.rc.readline_omit__names,
                                             self.alias_table)
         except ImportError,NameError:
             # If FlexCompleter failed to import, MagicCompleter won't be 
             # defined.  This can happen because of a problem with readline
             self.has_readline = 0
             # no point in bugging windows users with this every time:
             if os.name == 'posix':
                 warn('Readline services not available on this platform.')
         else:
             import atexit
 
             # Platform-specific configuration
             if os.name == 'nt':
                 # readline under Windows modifies the default exit behavior
                 # from being Ctrl-Z/Return to the Unix Ctrl-D one.
                 __builtin__.exit = __builtin__.quit = \
                      ('Use Ctrl-D (i.e. EOF) to exit. '
                       'Use %Exit or %Quit to exit without confirmation.')
                 self.readline_startup_hook = readline.set_pre_input_hook
             else:
                 self.readline_startup_hook = readline.set_startup_hook
 
             # Load user's initrc file (readline config)
             inputrc_name = os.environ.get('INPUTRC')
             if inputrc_name is None:
                 home_dir = get_home_dir()
                 if home_dir is not None:
                     inputrc_name = os.path.join(home_dir,'.inputrc')
             if os.path.isfile(inputrc_name):
                 try:
                     readline.read_init_file(inputrc_name)
                 except:
                     warn('Problems reading readline initialization file <%s>'
                          % inputrc_name)
             
             self.has_readline = 1
             self.readline = readline
             self.readline_indent = 0  # for auto-indenting via readline
             # save this in sys so embedded copies can restore it properly
             sys.ipcompleter = self.Completer.complete
             readline.set_completer(self.Completer.complete)
 
             # Configure readline according to user's prefs
             for rlcommand in self.rc.readline_parse_and_bind:
                 readline.parse_and_bind(rlcommand)
 
             # remove some chars from the delimiters list
             delims = readline.get_completer_delims()
             delims = delims.translate(string._idmap,
                                       self.rc.readline_remove_delims)
             readline.set_completer_delims(delims)
             # otherwise we end up with a monster history after a while:
             readline.set_history_length(1000)
             try:
                 #print '*** Reading readline history'  # dbg
                 readline.read_history_file(self.histfile)
             except IOError:
                 pass  # It doesn't exist yet.
 
             atexit.register(self.atexit_operations)
             del atexit
 
         # Configure auto-indent for all platforms
         self.set_autoindent(self.rc.autoindent)
 
     def showsyntaxerror(self, filename=None):
         """Display the syntax error that just occurred.
 
         This doesn't display a stack trace because there isn't one.
 
         If a filename is given, it is stuffed in the exception instead
         of what was there before (because Python's parser always uses
         "<string>" when reading from a string).
         """
         type, value, sys.last_traceback = sys.exc_info()
         sys.last_type = type
         sys.last_value = value
         if filename and type is SyntaxError:
             # Work hard to stuff the correct filename in the exception
             try:
                 msg, (dummy_filename, lineno, offset, line) = value
             except:
                 # Not the format we expect; leave it alone
                 pass
             else:
                 # Stuff in the right filename
                 try:
                     # Assume SyntaxError is a class exception
                     value = SyntaxError(msg, (filename, lineno, offset, line))
                 except:
                     # If that failed, assume SyntaxError is a string
                     value = msg, (filename, lineno, offset, line)
         self.SyntaxTB(type,value,[])
 
     def debugger(self):
         """Call the pdb debugger."""
 
         if not self.rc.pdb:
             return
         pdb.pm()
 
-    def showtraceback(self,exc_tuple = None):
+    def showtraceback(self,exc_tuple = None,filename=None):
         """Display the exception that just occurred."""
 
         # Though this won't be called by syntax errors in the input line,
         # there may be SyntaxError cases whith imported code.
         if exc_tuple is None:
             type, value, tb = sys.exc_info()
         else:
             type, value, tb = exc_tuple
         if type is SyntaxError:
-            self.showsyntaxerror()
+            self.showsyntaxerror(filename)
         else:
             sys.last_type = type
             sys.last_value = value
             sys.last_traceback = tb
             self.InteractiveTB()
             if self.InteractiveTB.call_pdb and self.has_readline:
                 # pdb mucks up readline, fix it back
                 self.readline.set_completer(self.Completer.complete)
 
     def update_cache(self, line):
         """puts line into cache"""
         self.inputcache.insert(0, line) # This copies the cache every time ... :-(
         if len(self.inputcache) >= self.CACHELENGTH:
             self.inputcache.pop()    # This not :-)
 
     def name_space_init(self):
         """Create local namespace."""
         # We want this to be a method to facilitate embedded initialization.
         code.InteractiveConsole.__init__(self,self.user_ns)
 
     def mainloop(self,banner=None):
         """Creates the local namespace and starts the mainloop.
 
         If an optional banner argument is given, it will override the
         internally created default banner."""
         
         self.name_space_init()
         if self.rc.c:  # Emulate Python's -c option
             self.exec_init_cmd()
         if banner is None:
             if self.rc.banner:
                 banner = self.BANNER+self.banner2
             else:
                 banner = ''
         self.interact(banner)
 
     def exec_init_cmd(self):
         """Execute a command given at the command line.
 
         This emulates Python's -c option."""
 
         sys.argv = ['-c']
         self.push(self.rc.c)
 
     def embed_mainloop(self,header='',local_ns=None,global_ns=None,stack_depth=0):
         """Embeds IPython into a running python program.
 
         Input:
 
           - header: An optional header message can be specified.
 
           - local_ns, global_ns: working namespaces. If given as None, the
           IPython-initialized one is updated with __main__.__dict__, so that
           program variables become visible but user-specific configuration
           remains possible.
 
           - stack_depth: specifies how many levels in the stack to go to
           looking for namespaces (when local_ns and global_ns are None).  This
           allows an intermediate caller to make sure that this function gets
           the namespace from the intended level in the stack.  By default (0)
           it will get its locals and globals from the immediate caller.
 
         Warning: it's possible to use this in a program which is being run by
         IPython itself (via %run), but some funny things will happen (a few
         globals get overwritten). In the future this will be cleaned up, as
         there is no fundamental reason why it can't work perfectly."""
 
         # Patch for global embedding to make sure that things don't overwrite
         # user globals accidentally. Thanks to Richard <[e-mail]>
         # FIXME. Test this a bit more carefully (the if.. is new)
         if local_ns is None and global_ns is None:
             self.user_ns.update(__main__.__dict__)
 
         # Get locals and globals from caller
         if local_ns is None or global_ns is None:
             call_frame = sys._getframe(stack_depth).f_back
 
             if local_ns is None:
                 local_ns = call_frame.f_locals
             if global_ns is None:
                 global_ns = call_frame.f_globals
 
         # Update namespaces and fire up interpreter
         self.user_ns.update(local_ns)
         self.interact(header)
 
         # Remove locals from namespace
         for k in local_ns:
             del self.user_ns[k]
 
     def interact(self, banner=None):
         """Closely emulate the interactive Python console.
 
         The optional banner argument specify the banner to print
         before the first interaction; by default it prints a banner
         similar to the one printed by the real Python interpreter,
         followed by the current class name in parentheses (so as not
         to confuse this with the real interpreter -- since it's so
         close!).
 
         """
         cprt = 'Type "copyright", "credits" or "license" for more information.'
         if banner is None:
             self.write("Python %s on %s\n%s\n(%s)\n" %
                        (sys.version, sys.platform, cprt,
                         self.__class__.__name__))
         else:
             self.write(banner)
 
         more = 0
 
         # Mark activity in the builtins
         __builtin__.__dict__['__IPYTHON__active'] += 1
 
         # exit_now is set by a call to %Exit or %Quit
         while not self.exit_now:
             try:
                 if more:
                     prompt = self.outputcache.prompt2
                     if self.autoindent:
                         self.readline_startup_hook(self.pre_readline)
                 else:
                     prompt = self.outputcache.prompt1
                 try:
                     line = self.raw_input(prompt)
                     if self.autoindent:
                         self.readline_startup_hook(None)
                 except EOFError:
                     if self.autoindent:
                         self.readline_startup_hook(None)
                     self.write("\n")
                     if self.rc.confirm_exit:
                         if ask_yes_no('Do you really want to exit ([y]/n)?','y'):
                             break
                     else:
                         break
                 else:
                     more = self.push(line)
                     # Auto-indent management
                     if self.autoindent:
                         if line:
                             ini_spaces = re.match('^(\s+)',line)
                             if ini_spaces:
                                 nspaces = ini_spaces.end()
                             else:
                                 nspaces = 0
                             self.readline_indent = nspaces
 
                             if line[-1] == ':':
                                 self.readline_indent += 4
                             elif re.match(r'^\s+raise|^\s+return',line):
                                 self.readline_indent -= 4
                         else:
                             self.readline_indent = 0
 
             except KeyboardInterrupt:
                 self.write("\nKeyboardInterrupt\n")
                 self.resetbuffer()
                 more = 0
                 # keep cache in sync with the prompt counter:
                 self.outputcache.prompt_count -= 1
 
                 if self.autoindent:
                     self.readline_indent = 0
 
             except bdb.BdbQuit:
                 warn("The Python debugger has exited with a BdbQuit exception.\n"
                      "Because of how pdb handles the stack, it is impossible\n"
                      "for IPython to properly format this particular exception.\n"
                      "IPython will resume normal operation.")
             
         # We are off again...
         __builtin__.__dict__['__IPYTHON__active'] -= 1
 
     def excepthook(self, type, value, tb):
       """One more defense for GUI apps that call sys.excepthook.
 
       GUI frameworks like wxPython trap exceptions and call
       sys.excepthook themselves.  I guess this is a feature that
       enables them to keep running after exceptions that would
       otherwise kill their mainloop. This is a bother for IPython
       which excepts to catch all of the program exceptions with a try:
       except: statement.
 
       Normally, IPython sets sys.excepthook to a CrashHandler instance, so if
       any app directly invokes sys.excepthook, it will look to the user like
       IPython crashed.  In order to work around this, we can disable the
       CrashHandler and replace it with this excepthook instead, which prints a
       regular traceback using our InteractiveTB.  In this fashion, apps which
       call sys.excepthook will generate a regular-looking exception from
       IPython, and the CrashHandler will only be triggered by real IPython
       crashes.
 
       This hook should be used sparingly, only in places which are not likely
       to be true IPython errors.
       """
       
       self.InteractiveTB(type, value, tb, tb_offset=0)
       if self.InteractiveTB.call_pdb and self.has_readline:
           self.readline.set_completer(self.Completer.complete)
 
     def call_alias(self,alias,rest=''):
         """Call an alias given its name and the rest of the line.
 
         This function MUST be given a proper alias, because it doesn't make
         any checks when looking up into the alias table.  The caller is
         responsible for invoking it only with a valid alias."""
 
         #print 'ALIAS: <%s>+<%s>' % (alias,rest) # dbg
         nargs,cmd = self.alias_table[alias]
         # Expand the %l special to be the user's input line
         if cmd.find('%l') >= 0:
             cmd = cmd.replace('%l',rest)
             rest = ''
         if nargs==0:
             # Simple, argument-less aliases
             cmd = '%s %s' % (cmd,rest)
         else:
             # Handle aliases with positional arguments
             args = rest.split(None,nargs)
             if len(args)< nargs:
                 error('Alias <%s> requires %s arguments, %s given.' %
                       (alias,nargs,len(args)))
                 return
             cmd = '%s %s' % (cmd % tuple(args[:nargs]),' '.join(args[nargs:]))
         # Now call the macro, evaluating in the user's namespace
         try:
             self.system(cmd)
         except:
             self.showtraceback()
 
     def runlines(self,lines):
         """Run a string of one or more lines of source.
 
         This method is capable of running a string containing multiple source
         lines, as if they had been entered at the IPython prompt.  Since it
         exposes IPython's processing machinery, the given strings can contain
         magic calls (%magic), special shell access (!cmd), etc."""
 
         # We must start with a clean buffer, in case this is run from an
         # interactive IPython session (via a magic, for example).
         self.resetbuffer()
         lines = lines.split('\n')
         more = 0
         for line in lines:
             # skip blank lines so we don't mess up the prompt counter, but do
             # NOT skip even a blank line if we are in a code block (more is
             # true)
             if line or more:
                 more = self.push((self.prefilter(line,more)))
                 # IPython's runsource returns None if there was an error
                 # compiling the code.  This allows us to stop processing right
                 # away, so the user gets the error message at the right place.
                 if more is None:
                     break
         # final newline in case the input didn't have it, so that the code
         # actually does get executed
         if more:
             self.push('\n')
 
     def runsource(self, source, filename="<input>", symbol="single"):
         """Compile and run some source in the interpreter.
 
         Arguments are as for compile_command().
 
         One several things can happen:
 
         1) The input is incorrect; compile_command() raised an
         exception (SyntaxError or OverflowError).  A syntax traceback
         will be printed by calling the showsyntaxerror() method.
 
         2) The input is incomplete, and more input is required;
         compile_command() returned None.  Nothing happens.
 
         3) The input is complete; compile_command() returned a code
         object.  The code is executed by calling self.runcode() (which
         also handles run-time exceptions, except for SystemExit).
 
         The return value is:
 
           - True in case 2
 
           - False in the other cases, unless an exception is raised, where
           None is returned instead.  This can be used by external callers to
           know whether to continue feeding input or not.
 
         The return value can be used to decide whether to use sys.ps1 or
         sys.ps2 to prompt the next line."""
 
         try:
             code = self.compile(source, filename, symbol)
         except (OverflowError, SyntaxError, ValueError):
             # Case 1
             self.showsyntaxerror(filename)
             return None
 
         if code is None:
             # Case 2
             return True
 
         # Case 3
         # We store the code object so that threaded shells and
         # custom exception handlers can access all this info if needed.
         # The source corresponding to this can be obtained from the
         # buffer attribute as '\n'.join(self.buffer).
         self.code_to_run = code
         # now actually execute the code object
         if self.runcode(code) == 0:
             return False
         else:
             return None
 
     def runcode(self,code_obj):
         """Execute a code object.
 
         When an exception occurs, self.showtraceback() is called to display a
         traceback.
 
         Return value: a flag indicating whether the code to be run completed
         successfully:
 
           - 0: successful execution.
           - 1: an error occurred.
         """
 
         # Set our own excepthook in case the user code tries to call it
         # directly, so that the IPython crash handler doesn't get triggered
         old_excepthook,sys.excepthook = sys.excepthook, self.excepthook
         outflag = 1  # happens in more places, so it's easier as default
         try:
             try:
                 exec code_obj in self.locals
             finally:
                 # Reset our crash handler in place
                 sys.excepthook = old_excepthook
         except SystemExit:
             self.resetbuffer()
             self.showtraceback()
             warn( __builtin__.exit,level=1)
         except self.custom_exceptions:
             etype,value,tb = sys.exc_info()
             self.CustomTB(etype,value,tb)
         except:
             self.showtraceback()
         else:
             outflag = 0
             if code.softspace(sys.stdout, 0):
                 print
         # Flush out code object which has been run (and source)
         self.code_to_run = None
         return outflag
 
     def raw_input(self, prompt=""):
         """Write a prompt and read a line.
 
         The returned line does not include the trailing newline.
         When the user enters the EOF key sequence, EOFError is raised.
 
         The base implementation uses the built-in function
         raw_input(); a subclass may replace this with a different
         implementation.
         """
         return self.prefilter(raw_input_original(prompt),
                               prompt==self.outputcache.prompt2)
         
     def split_user_input(self,line):
         """Split user input into pre-char, function part and rest."""
 
         lsplit = self.line_split.match(line)
         if lsplit is None:  # no regexp match returns None
             try:
                 iFun,theRest = line.split(None,1)
             except ValueError:
                 iFun,theRest = line,''
             pre = re.match('^(\s*)(.*)',line).groups()[0]
         else:
             pre,iFun,theRest = lsplit.groups()
 
         #print 'line:<%s>' % line # dbg
         #print 'pre <%s> iFun <%s> rest <%s>' % (pre,iFun.strip(),theRest) # dbg
         return pre,iFun.strip(),theRest
 
     def _prefilter(self, line, continue_prompt):
         """Calls different preprocessors, depending on the form of line."""
 
         # All handlers *must* return a value, even if it's blank ('').
 
         # Lines are NOT logged here. Handlers should process the line as
         # needed, update the cache AND log it (so that the input cache array
         # stays synced).
 
         # This function is _very_ delicate, and since it's also the one which
         # determines IPython's response to user input, it must be as efficient
         # as possible.  For this reason it has _many_ returns in it, trying
         # always to exit as quickly as it can figure out what it needs to do.
 
         # This function is the main responsible for maintaining IPython's
         # behavior respectful of Python's semantics.  So be _very_ careful if
         # making changes to anything here.
 
         #.....................................................................
         # Code begins
 
         #if line.startswith('%crash'): raise RuntimeError,'Crash now!'  # dbg
 
         # save the line away in case we crash, so the post-mortem handler can
         # record it
         self._last_input_line = line
 
         #print '***line: <%s>' % line # dbg
 
         # the input history needs to track even empty lines
         if not line.strip():
             if not continue_prompt:
                 self.outputcache.prompt_count -= 1
             return self.handle_normal('',continue_prompt)
 
         # print '***cont',continue_prompt  # dbg
         # special handlers are only allowed for single line statements
         if continue_prompt and not self.rc.multi_line_specials:
             return self.handle_normal(line,continue_prompt)
 
         # For the rest, we need the structure of the input
         pre,iFun,theRest = self.split_user_input(line)
         #print 'pre <%s> iFun <%s> rest <%s>' % (pre,iFun,theRest)  # dbg
 
         # First check for explicit escapes in the last/first character
         handler = None
         if line[-1] == self.ESC_HELP:
             handler = self.esc_handlers.get(line[-1])  # the ? can be at the end
         if handler is None:
             # look at the first character of iFun, NOT of line, so we skip
             # leading whitespace in multiline input
             handler = self.esc_handlers.get(iFun[0:1])
         if handler is not None:
             return handler(line,continue_prompt,pre,iFun,theRest)
         # Emacs ipython-mode tags certain input lines
         if line.endswith('# PYTHON-MODE'):
             return self.handle_emacs(line,continue_prompt)
 
         # Next, check if we can automatically execute this thing
 
         # Allow ! in multi-line statements if multi_line_specials is on:
         if continue_prompt and self.rc.multi_line_specials and \
                iFun.startswith(self.ESC_SHELL):
             return self.handle_shell_escape(line,continue_prompt,
                                             pre=pre,iFun=iFun,
                                             theRest=theRest)
 
         # Let's try to find if the input line is a magic fn
         oinfo = None
         if hasattr(self,'magic_'+iFun):
             oinfo = self._ofind(iFun) # FIXME - _ofind is part of Magic
             if oinfo['ismagic']:
                 # Be careful not to call magics when a variable assignment is
                 # being made (ls='hi', for example)
                 if self.rc.automagic and \
                        (len(theRest)==0 or theRest[0] not in '!=()<>,') and \
                        (self.rc.multi_line_specials or not continue_prompt):
                     return self.handle_magic(line,continue_prompt,
                                              pre,iFun,theRest)
                 else:
                     return self.handle_normal(line,continue_prompt)
 
         # If the rest of the line begins with an (in)equality, assginment or
         # function call, we should not call _ofind but simply execute it.
         # This avoids spurious geattr() accesses on objects upon assignment.
         #
         # It also allows users to assign to either alias or magic names true
         # python variables (the magic/alias systems always take second seat to
         # true python code).
         if theRest and theRest[0] in '!=()':
             return self.handle_normal(line,continue_prompt)
 
         if oinfo is None:
             oinfo = self._ofind(iFun) # FIXME - _ofind is part of Magic
         
         if not oinfo['found']:
             return self.handle_normal(line,continue_prompt)
         else:
             #print 'iFun <%s> rest <%s>' % (iFun,theRest) # dbg
             if oinfo['isalias']:
                 return self.handle_alias(line,continue_prompt,
                                              pre,iFun,theRest)
 
             if self.rc.autocall and \
                    not self.re_exclude_auto.match(theRest) and \
                    self.re_fun_name.match(iFun) and \
                    callable(oinfo['obj']) :
                 #print 'going auto'  # dbg
                 return self.handle_auto(line,continue_prompt,pre,iFun,theRest)
             else:
                 #print 'was callable?', callable(oinfo['obj'])  # dbg
                 return self.handle_normal(line,continue_prompt)
 
         # If we get here, we have a normal Python line. Log and return.
         return self.handle_normal(line,continue_prompt)
 
     def _prefilter_dumb(self, line, continue_prompt):
         """simple prefilter function, for debugging"""
         return self.handle_normal(line,continue_prompt)
 
     # Set the default prefilter() function (this can be user-overridden)
     prefilter = _prefilter
 
     def handle_normal(self,line,continue_prompt=None,
                       pre=None,iFun=None,theRest=None):
         """Handle normal input lines. Use as a template for handlers."""
 
         self.log(line,continue_prompt)
         self.update_cache(line)
         return line
 
     def handle_alias(self,line,continue_prompt=None,
                      pre=None,iFun=None,theRest=None):
         """Handle alias input lines. """
 
         theRest = esc_quotes(theRest)
         line_out = "%s%s.call_alias('%s','%s')" % (pre,self.name,iFun,theRest)
         self.log(line_out,continue_prompt)
         self.update_cache(line_out)
         return line_out
 
     def handle_shell_escape(self, line, continue_prompt=None,
                             pre=None,iFun=None,theRest=None):
         """Execute the line in a shell, empty return value"""
 
         #print 'line in :', `line` # dbg
         # Example of a special handler. Others follow a similar pattern.
         if continue_prompt:  # multi-line statements
             if iFun.startswith('!!'):
                 print 'SyntaxError: !! is not allowed in multiline statements'
                 return pre
             else:
                 cmd = ("%s %s" % (iFun[1:],theRest)).replace('"','\\"')
                 line_out = '%s%s.system("%s")' % (pre,self.name,cmd)
                 #line_out = ('%s%s.system(' % (pre,self.name)) + repr(cmd) + ')'
         else: # single-line input
             if line.startswith('!!'):
                 # rewrite iFun/theRest to properly hold the call to %sx and
                 # the actual command to be executed, so handle_magic can work
                 # correctly
                 theRest = '%s %s' % (iFun[2:],theRest)
                 iFun = 'sx'
                 return self.handle_magic('%ssx %s' % (self.ESC_MAGIC,line[2:]),
                                          continue_prompt,pre,iFun,theRest)
             else:
                 cmd = esc_quotes(line[1:])
                 line_out = '%s.system("%s")' % (self.name,cmd)
                 #line_out = ('%s.system(' % self.name) + repr(cmd)+ ')'
         # update cache/log and return
         self.log(line_out,continue_prompt)
         self.update_cache(line_out)   # readline cache gets normal line
         #print 'line out r:', `line_out` # dbg
         #print 'line out s:', line_out # dbg
         return line_out
 
     def handle_magic(self, line, continue_prompt=None,
                      pre=None,iFun=None,theRest=None):
         """Execute magic functions.
 
         Also log them with a prepended # so the log is clean Python."""
 
         cmd = '%sipmagic("%s")' % (pre,esc_quotes('%s %s' % (iFun,theRest)))
         self.log(cmd,continue_prompt)
         self.update_cache(line)
         #print 'in handle_magic, cmd=<%s>' % cmd  # dbg
         return cmd
 
     def handle_auto(self, line, continue_prompt=None,
                     pre=None,iFun=None,theRest=None):
         """Hande lines which can be auto-executed, quoting if requested."""
 
         #print 'pre <%s> iFun <%s> rest <%s>' % (pre,iFun,theRest)  # dbg
         
         # This should only be active for single-line input!
         if continue_prompt:
             return line
 
         if pre == self.ESC_QUOTE:
             # Auto-quote splitting on whitespace
             newcmd = '%s("%s")' % (iFun,'", "'.join(theRest.split()) )
         elif pre == self.ESC_QUOTE2:
             # Auto-quote whole string
             newcmd = '%s("%s")' % (iFun,theRest)
         else:
             # Auto-paren
             if theRest[0:1] in ('=','['):
                 # Don't autocall in these cases.  They can be either
                 # rebindings of an existing callable's name, or item access
                 # for an object which is BOTH callable and implements
                 # __getitem__.
                 return '%s %s' % (iFun,theRest)
             if theRest.endswith(';'):
                 newcmd = '%s(%s);' % (iFun.rstrip(),theRest[:-1])
             else:
                 newcmd = '%s(%s)' % (iFun.rstrip(),theRest)
 
         print >>Term.cout, self.outputcache.prompt1.auto_rewrite() + newcmd
         # log what is now valid Python, not the actual user input (without the
         # final newline)
         self.log(newcmd,continue_prompt)
         return newcmd
 
     def handle_help(self, line, continue_prompt=None,
                     pre=None,iFun=None,theRest=None):
         """Try to get some help for the object.
 
         obj? or ?obj   -> basic information.
         obj?? or ??obj -> more details.
         """
 
         # We need to make sure that we don't process lines which would be
         # otherwise valid python, such as "x=1 # what?"
         try:
             code.compile_command(line)
         except SyntaxError:
             # We should only handle as help stuff which is NOT valid syntax
             if line[0]==self.ESC_HELP:
                 line = line[1:]
             elif line[-1]==self.ESC_HELP:
                 line = line[:-1]
             self.log('#?'+line)
             self.update_cache(line)
             if line:
                 self.magic_pinfo(line)
             else:
                 page(self.usage,screen_lines=self.rc.screen_length)
             return '' # Empty string is needed here!
         except:
             # Pass any other exceptions through to the normal handler
             return self.handle_normal(line,continue_prompt)
         else:
             # If the code compiles ok, we should handle it normally
             return self.handle_normal(line,continue_prompt)
 
     def handle_emacs(self,line,continue_prompt=None,
                     pre=None,iFun=None,theRest=None):
         """Handle input lines marked by python-mode."""
 
         # Currently, nothing is done.  Later more functionality can be added
         # here if needed.
 
         # The input cache shouldn't be updated
 
         return line
 
     def write(self,data):
         """Write a string to the default output"""
         Term.cout.write(data)
 
     def write_err(self,data):
         """Write a string to the default error output"""
         Term.cerr.write(data)
 
     def safe_execfile(self,fname,*where,**kw):
         fname = os.path.expanduser(fname)
 
         # find things also in current directory
         dname = os.path.dirname(fname)
         if not sys.path.count(dname):
             sys.path.append(dname)
 
         try:
             xfile = open(fname)
         except:
             print >> Term.cerr, \
                   'Could not open file <%s> for safe execution.' % fname
             return None
 
         kw.setdefault('islog',0)
         kw.setdefault('quiet',1)
         kw.setdefault('exit_ignore',0)
         first = xfile.readline()
         _LOGHEAD = str(self.LOGHEAD).split('\n',1)[0].strip()
         xfile.close()
         # line by line execution
         if first.startswith(_LOGHEAD) or kw['islog']:
             print 'Loading log file <%s> one line at a time...' % fname
             if kw['quiet']:
                 stdout_save = sys.stdout
                 sys.stdout = StringIO.StringIO()
             try:
                 globs,locs = where[0:2]
             except:
                 try:
                     globs = locs = where[0]
                 except:
                     globs = locs = globals()
             badblocks = []
 
             # we also need to identify indented blocks of code when replaying
             # logs and put them together before passing them to an exec
             # statement. This takes a bit of regexp and look-ahead work in the
             # file. It's easiest if we swallow the whole thing in memory
             # first, and manually walk through the lines list moving the
             # counter ourselves.
             indent_re = re.compile('\s+\S')
             xfile = open(fname)
             filelines = xfile.readlines()
             xfile.close()
             nlines = len(filelines)
             lnum = 0
             while lnum < nlines:
                 line = filelines[lnum]
                 lnum += 1
                 # don't re-insert logger status info into cache
                 if line.startswith('#log#'):
                     continue
                 elif line.startswith('#%s'% self.ESC_MAGIC):
                     self.update_cache(line[1:])
                     line = magic2python(line)
                 elif line.startswith('#!'):
                     self.update_cache(line[1:])
                 else:
                     # build a block of code (maybe a single line) for execution
                     block = line
                     try:
                         next = filelines[lnum] # lnum has already incremented
                     except:
                         next = None
                     while next and indent_re.match(next):
                         block += next
                         lnum += 1
                         try:
                             next = filelines[lnum]
                         except:
                             next = None
                     # now execute the block of one or more lines
                     try:
                         exec block in globs,locs
                         self.update_cache(block.rstrip())
                     except SystemExit:
                         pass
                     except:
                         badblocks.append(block.rstrip())
             if kw['quiet']:  # restore stdout
                 sys.stdout.close()
                 sys.stdout = stdout_save
             print 'Finished replaying log file <%s>' % fname
             if badblocks:
                 print >> sys.stderr, \
                       '\nThe following lines/blocks in file <%s> reported errors:' \
                       % fname
                 for badline in badblocks:
                     print >> sys.stderr, badline
         else:  # regular file execution
             try:
                 execfile(fname,*where)
             except SyntaxError:
                 etype, evalue = sys.exc_info()[0:2]
                 self.SyntaxTB(etype,evalue,[])
                 warn('Failure executing file: <%s>' % fname)
             except SystemExit,status:
                 if not kw['exit_ignore']:
                     self.InteractiveTB()
                     warn('Failure executing file: <%s>' % fname)
             except:
                 self.InteractiveTB()
                 warn('Failure executing file: <%s>' % fname)
 
 #************************* end of file <iplib.py> *****************************