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Add new winconsole module and fixes to page_dumb() to improve its behavior...
Add new winconsole module and fixes to page_dumb() to improve its behavior under win32. Contributed by Alexander Belchenko <bialix-AT-ukr.net>.

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# -*- 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 971 2005-12-29 18:30:45Z fperez $"""
# Copyright (C) 2001-2004 Fernando Perez. <fperez@colorado.edu>
# 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 from the Python standard library
import __main__
import commands
import os
import re
import shlex
import shutil
import sys
import tempfile
import time
import types
# Other IPython utilities
from IPython.Itpl import Itpl,itpl,printpl
from IPython import DPyGetOpt
if os.name == "nt":
from IPython.winconsole import get_console_size
# Build objects which appeared in Python 2.3 for 2.2, to make ipython
# 2.2-friendly
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
# Try to use shlex.split for converting an input string into a sys.argv-type
# list. This appeared in Python 2.3, so here's a quick backport for 2.2.
shlex_split = shlex.split
except AttributeError:
_quotesre = re.compile(r'[\'"](.*)[\'"]')
_wordchars = ('abcdfeghijklmnopqrstuvwxyz'
% os.sep)
def shlex_split(s):
"""Simplified backport to Python 2.2 of shlex.split().
This is a quick and dirty hack, since the shlex module under 2.2 lacks
several of the features needed to really match the functionality of
shlex.split() in 2.3."""
lex = shlex.shlex(StringIO(s))
# Try to get options, extensions and path separators as characters
lex.wordchars = _wordchars
lex.commenters = ''
# Make a list out of the lexer by hand, since in 2.2 it's not an
# iterator.
lout = []
while 1:
token = lex.get_token()
if token == '':
# Try to handle quoted tokens correctly
quotes = _quotesre.match(token)
if quotes:
token = quotes.group(1)
return lout
# Exceptions
class Error(Exception):
"""Base class for exceptions in this module."""
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):
# 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,
# 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
# 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':
import readline
except ImportError:
_out = readline.GetOutputFile()
except AttributeError:
# 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).
-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'
def info(msg):
"""Equivalent to warn(msg,level=1)."""
def error(msg):
"""Equivalent to warn(msg,level=3)."""
def fatal(msg,exit_val=1):
"""Equivalent to 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()
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
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
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.
- 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
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.
- 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
if not debug:
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')
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
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 [],[]
return '',''
if not debug:
pin,pout,perr = os.popen3(cmd)
tout = pout.read().rstrip()
terr = perr.read().rstrip()
if split:
return tout.split('\n'),terr.split('\n')
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
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."""
def shell(self,cmd):
"""Stateful interface to shell(), with the same keyword parameters."""
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
raise IOError,'File `%s` not found.' % name
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:
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 file_read(filename):
"""Read a file and close it. Returns the file source."""
source = fobj.read();
return source
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.
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):
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]
return istr
def process_cmdline(argv,names=[],defaults={},usage=''):
""" Process command-line options and arguments.
- argv: list of arguments, typically sys.argv.
- names: list of option names. See DPyGetOpt docs for details on options
- 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()
print usage
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
- 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.
If the input file test.ini has:
i 3
x 4.5
y 5.5
s hi ho
>>> 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('fs',None) # field sep defaults to any whitespace
if type(opt['unique']) in StringTypes:
unique_keys = qw(opt['unique'])
elif type(opt['unique']) in (types.TupleType,types.ListType):
unique_keys = opt['unique']
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)
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()):
# 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.
if dict[key] and key in unique_keys:
dict[key] = val
elif type(dict[key]) is types.ListType:
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
# 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]):
dict[val] = convert(dict[val])
except KeyError,e:
if opt['warn'] == 0:
elif opt['warn'] == 1:
print >>sys.stderr, 'Warning: key',val,\
'not found in file',filename
elif opt['warn'] == 2:
raise KeyError,e
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):
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
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.
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
# 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]
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.' %
raise HomeDirError(e)
return homedir
except HomeDirError:
return 'C:\\'
elif os.name == 'dos':
# Desperate, may do absurd things in classic MacOS. May work under DOS.
return 'C:\\'
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
Such strings are very useful to efficiently interact with the shell, which
typically only understands whitespace-separated options for commands."""
def get_list(self):
return self.__list
except AttributeError:
self.__list = self.split('\n')
return self.__list
l = list = property(get_list)
def get_spstr(self):
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
def get_list(self):
return self
l = list = property(get_list)
def get_spstr(self):
return self.__spstr
except AttributeError:
self.__spstr = ' '.join(self)
return self.__spstr
s = spstr = property(get_spstr)
def get_nlstr(self):
return self.__nlstr
except AttributeError:
self.__nlstr = '\n'.join(self)
return self.__nlstr
n = nlstr = property(get_nlstr)
# This can be replaced with an isspace() call once we drop 2.2 compatibility
_isspace_match = re.compile(r'^\s+$').match
def isspace(s):
return bool(_isspace_match(s))
def esc_quotes(strng):
"""Return the input string with single and double quotes escaped out"""
return strng.replace('"','\\"').replace("'","\\'")
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.
if header:
header += '\n'
lines = [raw_input(header + ps1)]
except EOFError:
return []
terminate = [terminate_str]
while lines[-1:] != terminate:
new_line = raw_input(ps1)
while new_line.endswith('\\'):
new_line = new_line[:-1] + raw_input(ps2)
return lines[:-1] # don't return the termination command
except EOFError:
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
Valid answers are: y/yes/n/no (match is not case sensitive)."""
answers = {'y':True,'n':False,'yes':True,'no':False}
ans = None
eofs, max_eofs = 0, 20
while ans not in answers.keys():
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
return answers[ans]
def marquee(txt='',width=78,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.
>>>number = 19
>>>text = "python"
>>>print "%(text.capitalize())s %(number/9.0).1f rules!" % EvalDict()
# 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)]
return qw(indata)
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.
if case:
for term in list:
if term.find(pat)>-1: out.append(term)
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:
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)]
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()
new = open(filename,'wb')
new.write(os.linesep) # ALWAYS put an eol at the end of the file
if not backup:
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:
pager_cmd = os.environ['PAGER']
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)
start_string = ''
start_string = ''
return start_string
if os.name == "nt":
import msvcrt
def page_more():
""" Smart pausing between pages
@return: True if need print more lines, False if quit
Term.cout.write('---Return to continue, q to quit--- ')
ans = msvcrt.getch()
if ans in ("q", "Q"):
result = False
result = True
Term.cout.write("\b"*37 + " "*37 + "\b"*37)
return result
def page_more():
ans = raw_input('---Return to continue, q to quit--- ')
if ans.lower().startswith('q'):
return False
return True
esc_re = re.compile(r"(\x1b[^m]+m)")
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
out_ln = strng.splitlines()[start:]
screens = chop(out_ln,screen_lines-1)
if len(screens) == 1:
print >>Term.cout, os.linesep.join(screens[0])
last_escape = ""
for scr in screens[0:-1]:
hunk = os.linesep.join(scr)
print >>Term.cout, last_escape + hunk
if not page_more():
esc_list = esc_re.findall(hunk)
if len(esc_list) > 0:
last_escape = esc_list[-1]
print >>Term.cout, last_escape + 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
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
# 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)
if os.name == "nt":
screen_lines_def = get_console_size(defaulty=25)[1]
screen_lines_def = 25 # default value if we can't auto-determine
# auto-determine screen size
if screen_lines <= 0:
if TERM=='xterm':
import curses
if hasattr(curses,'initscr'):
use_curses = 1
use_curses = 0
except ImportError:
use_curses = 0
# 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()
screen_lines += screen_lines_real
#print '***Screen size:',screen_lines_real,'lines x',\
#screen_cols,'columns.' # dbg
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
# 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
tmpname = tempfile.mktemp('.txt')
tmpfile = file(tmpname,'wt')
cmd = "%s < %s" % (pager_cmd,tmpname)
if os.system(cmd):
retval = 1
retval = None
retval = None
# if I use popen4, things hang. No idea why.
#pager,shell_out = os.popen4(pager_cmd)
pager = os.popen(pager_cmd,'w')
retval = pager.close() # success returns None
except IOError,msg: # broken pipe when user quits
if msg.args == (32,'Broken pipe'):
retval = None
retval = 1
except OSError:
# Other strange problems, sometimes seen in Win2k/cygwin
retval = 1
if retval is not None:
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)
if os.environ['TERM'] in ['emacs','dumb']:
raise EnvironmentError
xsys(pager_cmd + ' ' + fname)
if start > 0:
start -= 1
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:
return 0
print header,
if len(str) < width:
print str
snip = 0
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':
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
unique = []
unique_dict = {}
for nn in elems:
if nn not in unique_dict:
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
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',': ')
# 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.depth -= 1
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:
elif size == 1:
dic[elem] = default
k,v = elem[0], elem[1:]
if len(v) == 1: v = v[0]
dic[k] = v
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.
born = 1960,
haircolour = 'Brown',
eyecolour = 'Green')
Credit: Greg Ewing, in
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)
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)
raise ValueError,'getattr_list() takes only one optional argument'
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:
handler = getattr(object, method)
except AttributeError:
if argseq:
args = map(lambda lst:lst[idx],argseq)
#print 'ob',object,'hand',handler,'ar',args # dbg
idx += 1
return out_list
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,))
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. """
val = dct[key]
except KeyError:
if default is NotGiven:
return default
del dct[key]
return val
#*************************** end of file <genutils.py> **********************