# -*- 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. """ #***************************************************************************** # Copyright (C) 2001-2006 Fernando Perez. # # Distributed under the terms of the BSD License. The full license is in # the file COPYING, distributed as part of this software. #***************************************************************************** #**************************************************************************** # required modules from the Python standard library import __main__ import os import platform import re import shlex import shutil import subprocess import sys import time import types import warnings # Curses and termios are Unix-only modules try: import curses # We need termios as well, so if its import happens to raise, we bail on # using curses altogether. import termios except ImportError: USE_CURSES = False else: # Curses on Solaris may not be complete, so we can't use it there USE_CURSES = hasattr(curses,'initscr') # Other IPython utilities import IPython from IPython.external.Itpl import itpl,printpl from IPython.utils import platutils from IPython.utils.generics import result_display from IPython.external.path import path #**************************************************************************** # 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:', self.stream def close(self): pass 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() import IPython.utils.rlineimpl as readline # Remake Term to use the readline i/o facilities if sys.platform == 'win32' and readline.have_readline: Term = IOTerm(cout=readline._outputfile,cerr=readline._outputfile) #**************************************************************************** # 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) #--------------------------------------------------------------------------- # Debugging routines # def debugx(expr,pre_msg=''): """Print the value of an expression from the caller's frame. Takes an expression, evaluates it in the caller's frame and prints both the given expression and the resulting value (as well as a debug mark indicating the name of the calling function. The input must be of a form suitable for eval(). An optional message can be passed, which will be prepended to the printed expr->value pair.""" cf = sys._getframe(1) print '[DBG:%s] %s%s -> %r' % (cf.f_code.co_name,pre_msg,expr, eval(expr,cf.f_globals,cf.f_locals)) # deactivate it by uncommenting the following line, which makes it a no-op #def debugx(expr,pre_msg=''): pass #---------------------------------------------------------------------------- StringTypes = types.StringTypes # Basic timing functionality # If possible (Unix), use the resource module instead of time.clock() try: import resource def clocku(): """clocku() -> floating point number Return the *USER* CPU time in seconds 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 clocks(): """clocks() -> floating point number Return the *SYSTEM* CPU time in seconds 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)[1] def clock(): """clock() -> floating point number Return the *TOTAL USER+SYSTEM* CPU time in seconds since the start of the process. This is done via a call to resource.getrusage, so it avoids the wraparound problems in time.clock().""" u,s = resource.getrusage(resource.RUSAGE_SELF)[:2] return u+s 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: # There is no distinction of user/system time under windows, so we just use # time.clock() for everything... clocku = clocks = 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 arg_split(s,posix=False): """Split a command line's arguments in a shell-like manner. This is a modified version of the standard library's shlex.split() function, but with a default of posix=False for splitting, so that quotes in inputs are respected.""" # XXX - there may be unicode-related problems here!!! I'm not sure that # shlex is truly unicode-safe, so it might be necessary to do # # s = s.encode(sys.stdin.encoding) # # first, to ensure that shlex gets a normal string. Input from anyone who # knows more about unicode and shlex than I would be good to have here... lex = shlex.shlex(s, posix=posix) lex.whitespace_split = True return list(lex) 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 abbrev_cwd(): """ Return abbreviated version of cwd, e.g. d:mydir """ cwd = os.getcwd().replace('\\','/') drivepart = '' tail = cwd if sys.platform == 'win32': if len(cwd) < 4: return cwd drivepart,tail = os.path.splitdrive(cwd) parts = tail.split('/') if len(parts) > 2: tail = '/'.join(parts[-2:]) return (drivepart + ( cwd == '/' and '/' or tail)) # This function is used by ipython in a lot of places to make system calls. # We need it to be slightly different under win32, due to the vagaries of # 'network shares'. A win32 override is below. 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: platutils.set_term_title("IPy " + cmd) os.system(cmd) platutils.set_term_title("IPy " + abbrev_cwd()) # override shell() for win32 to deal with network shares if os.name in ('nt','dos'): shell_ori = shell def shell(cmd,verbose=0,debug=0,header=''): if os.getcwd().startswith(r"\\"): path = os.getcwd() # change to c drive (cannot be on UNC-share when issuing os.system, # as cmd.exe cannot handle UNC addresses) os.chdir("c:") # issue pushd to the UNC-share and then run the command try: shell_ori('"pushd %s&&"'%path+cmd,verbose,debug,header) finally: os.chdir(path) else: shell_ori(cmd,verbose,debug,header) shell.__doc__ = shell_ori.__doc__ 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. This is pretty much deprecated and rarely used, genutils.getoutputerror may be what you need. """ if verbose or debug: print header+cmd if not debug: pipe = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE).stdout output = pipe.read() # stipping last \n is here for backwards compat. if output.endswith('\n'): output = output[:-1] 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: p = subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, close_fds=True) pin, pout, perr = (p.stdin, p.stdout, p.stderr) 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: ') """ 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 get_py_filename(name): """Return a valid python filename in the current directory. If the given name is not a file, it adds '.py' and searches again. Raises IOError with an informative message if the file isn't found.""" name = os.path.expanduser(name) if not os.path.isfile(name) and not name.endswith('.py'): name += '.py' if os.path.isfile(name): return name else: raise IOError,'File `%s` not found.' % name #----------------------------------------------------------------------------- def filefind(filename, path_dirs=None): """Find a file by looking through a sequence of paths. This iterates through a sequence of paths looking for a file and returns the full, absolute path of the first occurence of the file. If no set of path dirs is given, the filename is tested as is, after running through :func:`expandvars` and :func:`expanduser`. Thus a simple call:: filefind('myfile.txt') will find the file in the current working dir, but:: filefind('~/myfile.txt') Will find the file in the users home directory. This function does not automatically try any paths, such as the cwd or the user's home directory. Parameters ---------- filename : str The filename to look for. path_dirs : str, None or sequence of str The sequence of paths to look for the file in. If None, the filename need to be absolute or be in the cwd. If a string, the string is put into a sequence and the searched. If a sequence, walk through each element and join with ``filename``, calling :func:`expandvars` and :func:`expanduser` before testing for existence. Returns ------- Raises :exc:`IOError` or returns absolute path to file. """ if path_dirs is None: path_dirs = ("",) elif isinstance(path_dirs, basestring): path_dirs = (path_dirs,) for path in path_dirs: if path == '.': path = os.getcwd() testname = expand_path(os.path.join(path, filename)) if os.path.isfile(testname): return os.path.abspath(testname) raise IOError("File does not exist in any " "of the search paths: %r, %r" % \ (filename, path_dirs)) #---------------------------------------------------------------------------- def file_read(filename): """Read a file and close it. Returns the file source.""" fobj = open(filename,'r'); source = fobj.read(); fobj.close() return source def file_readlines(filename): """Read a file and close it. Returns the file source using readlines().""" fobj = open(filename,'r'); lines = fobj.readlines(); fobj.close() return lines #---------------------------------------------------------------------------- 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 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 #---------------------------------------------------------------------------- def dhook_wrap(func,*a,**k): """Wrap a function call in a sys.displayhook controller. Returns a wrapper around func which calls func, with all its arguments and keywords unmodified, using the default sys.displayhook. Since IPython modifies sys.displayhook, it breaks the behavior of certain systems that rely on the default behavior, notably doctest. """ def f(*a,**k): dhook_s = sys.displayhook sys.displayhook = sys.__displayhook__ try: out = func(*a,**k) finally: sys.displayhook = dhook_s return out f.__doc__ = func.__doc__ return f #---------------------------------------------------------------------------- def doctest_reload(): """Properly reload doctest to reuse it interactively. This routine: - imports doctest but does NOT reload it (see below). - resets its global 'master' attribute to None, so that multiple uses of the module interactively don't produce cumulative reports. - Monkeypatches its core test runner method to protect it from IPython's modified displayhook. Doctest expects the default displayhook behavior deep down, so our modification breaks it completely. For this reason, a hard monkeypatch seems like a reasonable solution rather than asking users to manually use a different doctest runner when under IPython. Notes ----- This function *used to* reload doctest, but this has been disabled because reloading doctest unconditionally can cause massive breakage of other doctest-dependent modules already in memory, such as those for IPython's own testing system. The name wasn't changed to avoid breaking people's code, but the reload call isn't actually made anymore.""" import doctest doctest.master = None doctest.DocTestRunner.run = dhook_wrap(doctest.DocTestRunner.run) #---------------------------------------------------------------------------- class HomeDirError(Error): pass def get_home_dir(): """Return the closest possible equivalent to a 'home' directory. * On POSIX, we try $HOME. * On Windows we try: - %HOMESHARE% - %HOMEDRIVE\%HOMEPATH% - %USERPROFILE% - Registry hack * On Dos C:\ Currently only Posix and NT are implemented, a HomeDirError exception is raised for all other OSes. """ isdir = os.path.isdir env = os.environ # first, check py2exe distribution root directory for _ipython. # This overrides all. Normally does not exist. if hasattr(sys, "frozen"): #Is frozen by py2exe if '\\library.zip\\' in IPython.__file__.lower():#libraries compressed to zip-file root, rest = IPython.__file__.lower().split('library.zip') else: root=os.path.join(os.path.split(IPython.__file__)[0],"../../") root=os.path.abspath(root).rstrip('\\') if isdir(os.path.join(root, '_ipython')): os.environ["IPYKITROOT"] = root return root.decode(sys.getfilesystemencoding()) if os.name == 'posix': # Linux, Unix, AIX, OS X try: homedir = env['HOME'] except KeyError: raise HomeDirError('Undefined $HOME, IPython cannot proceed.') else: return homedir.decode(sys.getfilesystemencoding()) elif os.name == 'nt': # Now for win9x, XP, Vista, 7? # For some strange reason all of these return 'nt' for os.name. # First look for a network home directory. This will return the UNC # path (\\server\\Users\%username%) not the mapped path (Z:\). This # is needed when running IPython on cluster where all paths have to # be UNC. try: homedir = env['HOMESHARE'] except KeyError: pass else: if isdir(homedir): return homedir.decode(sys.getfilesystemencoding()) # Now look for a local home directory try: homedir = os.path.join(env['HOMEDRIVE'],env['HOMEPATH']) except KeyError: pass else: if isdir(homedir): return homedir.decode(sys.getfilesystemencoding()) # Now the users profile directory try: homedir = os.path.join(env['USERPROFILE']) except KeyError: pass else: if isdir(homedir): return homedir.decode(sys.getfilesystemencoding()) # Use the registry to get the 'My Documents' folder. try: 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() except: pass else: if isdir(homedir): return homedir.decode(sys.getfilesystemencoding()) # If all else fails, raise HomeDirError raise HomeDirError('No valid home directory could be found') elif os.name == 'dos': # Desperate, may do absurd things in classic MacOS. May work under DOS. return 'C:\\'.decode(sys.getfilesystemencoding()) else: raise HomeDirError('No valid home directory could be found for your OS') def get_ipython_dir(): """Get the IPython directory for this platform and user. This uses the logic in `get_home_dir` to find the home directory and the adds .ipython to the end of the path. """ ipdir_def = '.ipython' home_dir = get_home_dir() ipdir = os.environ.get( 'IPYTHON_DIR', os.environ.get( 'IPYTHONDIR', os.path.join(home_dir, ipdir_def) ) ) return ipdir.decode(sys.getfilesystemencoding()) def get_ipython_package_dir(): """Get the base directory where IPython itself is installed.""" ipdir = os.path.dirname(IPython.__file__) return ipdir.decode(sys.getfilesystemencoding()) #**************************************************************************** # 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. .p (or .paths): list of path objects 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) def get_paths(self): try: return self.__paths except AttributeError: self.__paths = [path(p) for p in self.split('\n') if os.path.exists(p)] return self.__paths p = paths = property(get_paths) def print_lsstring(arg): """ Prettier (non-repr-like) and more informative printer for LSString """ print "LSString (.p, .n, .l, .s available). Value:" print arg print_lsstring = result_display.when_type(LSString)(print_lsstring) #---------------------------------------------------------------------------- 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. .p (or .paths): list of path objects 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 get_paths(self): try: return self.__paths except AttributeError: self.__paths = [path(p) for p in self if os.path.exists(p)] return self.__paths p = paths = property(get_paths) def grep(self, pattern, prune = False, field = None): """ Return all strings matching 'pattern' (a regex or callable) This is case-insensitive. If prune is true, return all items NOT matching the pattern. If field is specified, the match must occur in the specified whitespace-separated field. Examples:: a.grep( lambda x: x.startswith('C') ) a.grep('Cha.*log', prune=1) a.grep('chm', field=-1) """ def match_target(s): if field is None: return s parts = s.split() try: tgt = parts[field] return tgt except IndexError: return "" if isinstance(pattern, basestring): pred = lambda x : re.search(pattern, x, re.IGNORECASE) else: pred = pattern if not prune: return SList([el for el in self if pred(match_target(el))]) else: return SList([el for el in self if not pred(match_target(el))]) def fields(self, *fields): """ Collect whitespace-separated fields from string list Allows quick awk-like usage of string lists. Example data (in var a, created by 'a = !ls -l'):: -rwxrwxrwx 1 ville None 18 Dec 14 2006 ChangeLog drwxrwxrwx+ 6 ville None 0 Oct 24 18:05 IPython a.fields(0) is ['-rwxrwxrwx', 'drwxrwxrwx+'] a.fields(1,0) is ['1 -rwxrwxrwx', '6 drwxrwxrwx+'] (note the joining by space). a.fields(-1) is ['ChangeLog', 'IPython'] IndexErrors are ignored. Without args, fields() just split()'s the strings. """ if len(fields) == 0: return [el.split() for el in self] res = SList() for el in [f.split() for f in self]: lineparts = [] for fd in fields: try: lineparts.append(el[fd]) except IndexError: pass if lineparts: res.append(" ".join(lineparts)) return res def sort(self,field= None, nums = False): """ sort by specified fields (see fields()) Example:: a.sort(1, nums = True) Sorts a by second field, in numerical order (so that 21 > 3) """ #decorate, sort, undecorate if field is not None: dsu = [[SList([line]).fields(field), line] for line in self] else: dsu = [[line, line] for line in self] if nums: for i in range(len(dsu)): numstr = "".join([ch for ch in dsu[i][0] if ch.isdigit()]) try: n = int(numstr) except ValueError: n = 0; dsu[i][0] = n dsu.sort() return SList([t[1] for t in dsu]) def print_slist(arg): """ Prettier (non-repr-like) and more informative printer for SList """ print "SList (.p, .n, .l, .s, .grep(), .fields(), sort() available):" if hasattr(arg, 'hideonce') and arg.hideonce: arg.hideonce = False return nlprint(arg) print_slist = result_display.when_type(SList)(print_slist) #---------------------------------------------------------------------------- def esc_quotes(strng): """Return the input string with single and double quotes escaped out""" return strng.replace('"','\\"').replace("'","\\'") #---------------------------------------------------------------------------- def make_quoted_expr(s): """Return string s in appropriate quotes, using raw string if possible. XXX - example removed because it caused encoding errors in documentation generation. We need a new example that doesn't contain invalid chars. Note the use of raw string and padding at the end to allow trailing backslash. """ tail = '' tailpadding = '' raw = '' if "\\" in s: raw = 'r' if s.endswith('\\'): tail = '[:-1]' tailpadding = '_' if '"' not in s: quote = '"' elif "'" not in s: quote = "'" elif '"""' not in s and not s.endswith('"'): quote = '"""' elif "'''" not in s and not s.endswith("'"): quote = "'''" else: # give up, backslash-escaped string will do return '"%s"' % esc_quotes(s) res = raw + quote + s + tailpadding + quote + tail return res #---------------------------------------------------------------------------- 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 a boolean (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. An EOF is treated as the default answer. 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':True,'n':False,'yes':True,'no':False} ans = None while ans not in answers.keys(): try: ans = raw_input(prompt+' ').lower() if not ans: # response was an empty string ans = default except KeyboardInterrupt: pass except EOFError: if default in answers.keys(): ans = default print else: raise return answers[ans] #---------------------------------------------------------------------------- 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() Python 2.1 rules! """ # This version is due to sismex01@hebmex.com on c.l.py, and is basically a # modified (shorter) version of: # http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/66018 by # Skip Montanaro (skip@pobox.com). 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 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 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 #**************************************************************************** # 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 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).""" 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)) #---------------------------------------------------------------------------- # with is a keyword as of python 2.5, so this function is renamed to withobj # from its old 'with' name. def with_obj(object, **args): """Set multiple attributes for an object, similar to Pascal's with. Example: with_obj(jim, born = 1960, haircolour = 'Brown', eyecolour = 'Green') Credit: Greg Ewing, in http://mail.python.org/pipermail/python-list/2001-May/040703.html. NOTE: up until IPython 0.7.2, this was called simply 'with', but 'with' has become a keyword for Python 2.5, so we had to rename it.""" 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 #---------------------------------------------------------------------------- def get_class_members(cls): ret = dir(cls) if hasattr(cls,'__bases__'): for base in cls.__bases__: ret.extend(get_class_members(base)) return ret #---------------------------------------------------------------------------- def dir2(obj): """dir2(obj) -> list of strings Extended version of the Python builtin dir(), which does a few extra checks, and supports common objects with unusual internals that confuse dir(), such as Traits and PyCrust. This version is guaranteed to return only a list of true strings, whereas dir() returns anything that objects inject into themselves, even if they are later not really valid for attribute access (many extension libraries have such bugs). """ # Start building the attribute list via dir(), and then complete it # with a few extra special-purpose calls. words = dir(obj) if hasattr(obj,'__class__'): words.append('__class__') words.extend(get_class_members(obj.__class__)) #if '__base__' in words: 1/0 # Some libraries (such as traits) may introduce duplicates, we want to # track and clean this up if it happens may_have_dupes = False # this is the 'dir' function for objects with Enthought's traits if hasattr(obj, 'trait_names'): try: words.extend(obj.trait_names()) may_have_dupes = True except TypeError: # This will happen if `obj` is a class and not an instance. pass # Support for PyCrust-style _getAttributeNames magic method. if hasattr(obj, '_getAttributeNames'): try: words.extend(obj._getAttributeNames()) may_have_dupes = True except TypeError: # `obj` is a class and not an instance. Ignore # this error. pass if may_have_dupes: # eliminate possible duplicates, as some traits may also # appear as normal attributes in the dir() call. words = list(set(words)) words.sort() # filter out non-string attributes which may be stuffed by dir() calls # and poor coding in third-party modules return [w for w in words if isinstance(w, basestring)] #---------------------------------------------------------------------------- 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)) #---------------------------------------------------------------------------- # 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 def wrap_deprecated(func, suggest = ''): def newFunc(*args, **kwargs): warnings.warn("Call to deprecated function %s, use %s instead" % ( func.__name__, suggest), category=DeprecationWarning, stacklevel = 2) return func(*args, **kwargs) return newFunc def _num_cpus_unix(): """Return the number of active CPUs on a Unix system.""" return os.sysconf("SC_NPROCESSORS_ONLN") def _num_cpus_darwin(): """Return the number of active CPUs on a Darwin system.""" p = subprocess.Popen(['sysctl','-n','hw.ncpu'],stdout=subprocess.PIPE) return p.stdout.read() def _num_cpus_windows(): """Return the number of active CPUs on a Windows system.""" return os.environ.get("NUMBER_OF_PROCESSORS") def num_cpus(): """Return the effective number of CPUs in the system as an integer. This cross-platform function makes an attempt at finding the total number of available CPUs in the system, as returned by various underlying system and python calls. If it can't find a sensible answer, it returns 1 (though an error *may* make it return a large positive number that's actually incorrect). """ # Many thanks to the Parallel Python project (http://www.parallelpython.com) # for the names of the keys we needed to look up for this function. This # code was inspired by their equivalent function. ncpufuncs = {'Linux':_num_cpus_unix, 'Darwin':_num_cpus_darwin, 'Windows':_num_cpus_windows, # On Vista, python < 2.5.2 has a bug and returns 'Microsoft' # See http://bugs.python.org/issue1082 for details. 'Microsoft':_num_cpus_windows, } ncpufunc = ncpufuncs.get(platform.system(), # default to unix version (Solaris, AIX, etc) _num_cpus_unix) try: ncpus = max(1,int(ncpufunc())) except: ncpus = 1 return ncpus def extract_vars(*names,**kw): """Extract a set of variables by name from another frame. :Parameters: - `*names`: strings One or more variable names which will be extracted from the caller's frame. :Keywords: - `depth`: integer (0) How many frames in the stack to walk when looking for your variables. Examples: In [2]: def func(x): ...: y = 1 ...: print extract_vars('x','y') ...: In [3]: func('hello') {'y': 1, 'x': 'hello'} """ depth = kw.get('depth',0) callerNS = sys._getframe(depth+1).f_locals return dict((k,callerNS[k]) for k in names) def extract_vars_above(*names): """Extract a set of variables by name from another frame. Similar to extractVars(), but with a specified depth of 1, so that names are exctracted exactly from above the caller. This is simply a convenience function so that the very common case (for us) of skipping exactly 1 frame doesn't have to construct a special dict for keyword passing.""" callerNS = sys._getframe(2).f_locals return dict((k,callerNS[k]) for k in names) def expand_path(s): """Expand $VARS and ~names in a string, like a shell :Examples: In [2]: os.environ['FOO']='test' In [3]: shexp('variable FOO is $FOO') Out[3]: 'variable FOO is test' """ # This is a pretty subtle hack. When expand user is given a UNC path # on Windows (\\server\share$\%username%), os.path.expandvars, removes # the $ to get (\\server\share\%username%). I think it considered $ # alone an empty var. But, we need the $ to remains there (it indicates # a hidden share). if os.name=='nt': s = s.replace('$\\', 'IPYTHON_TEMP') s = os.path.expandvars(os.path.expanduser(s)) if os.name=='nt': s = s.replace('IPYTHON_TEMP', '$\\') return s def list_strings(arg): """Always return a list of strings, given a string or list of strings as input. :Examples: In [7]: list_strings('A single string') Out[7]: ['A single string'] In [8]: list_strings(['A single string in a list']) Out[8]: ['A single string in a list'] In [9]: list_strings(['A','list','of','strings']) Out[9]: ['A', 'list', 'of', 'strings'] """ if isinstance(arg,basestring): return [arg] else: return arg #---------------------------------------------------------------------------- def marquee(txt='',width=78,mark='*'): """Return the input string centered in a 'marquee'. :Examples: In [16]: marquee('A test',40) Out[16]: '**************** A test ****************' In [17]: marquee('A test',40,'-') Out[17]: '---------------- A test ----------------' In [18]: marquee('A test',40,' ') Out[18]: ' A test ' """ 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) #*************************** end of file **********************