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* Refactored KernelManager to use Traitlets and to have its channels as attributes...
* Refactored KernelManager to use Traitlets and to have its channels as attributes * QtSubChannel and QtXReqChannel work now * Progress on refactoring FrontendWidget to use KernelManager.

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# encoding: utf-8
"""
Utilities for working with strings and text.
"""
#-----------------------------------------------------------------------------
# Copyright (C) 2008-2009 The IPython Development Team
#
# Distributed under the terms of the BSD License. The full license is in
# the file COPYING, distributed as part of this software.
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
import __main__
import os
import re
import shutil
import types
from IPython.external.path import path
from IPython.utils.generics import result_display
from IPython.utils.io import nlprint
from IPython.utils.data import flatten
#-----------------------------------------------------------------------------
# Code
#-----------------------------------------------------------------------------
StringTypes = types.StringTypes
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
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 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
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)