root / lib / compat.py @ f15a6b03
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# Copyright (C) 2010, 2011 Google Inc.
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful, but
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# WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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# General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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# 02110-1301, USA.
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"""Module containing backported language/library functionality.
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"""
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import itertools |
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import operator |
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try:
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# pylint: disable=F0401
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import functools |
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except ImportError: |
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functools = None
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try:
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# pylint: disable=F0401
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import roman |
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except ImportError: |
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roman = None
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# compat.md5_hash and compat.sha1_hash can be called to generate and md5 and a
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# sha1 hashing modules, under python 2.4, 2.5 and 2.6, even though some changes
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# went on. compat.sha1 is python-version specific and is used for python
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# modules (hmac, for example) which have changed their behavior as well from
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# one version to the other.
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try:
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# Yes, these don't always exist, that's why we're testing
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# Yes, we're not using the imports in this module.
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from hashlib import md5 as md5_hash # pylint: disable=W0611,E0611,F0401 |
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from hashlib import sha1 as sha1_hash # pylint: disable=W0611,E0611,F0401 |
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# this additional version is needed for compatibility with the hmac module
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sha1 = sha1_hash |
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except ImportError: |
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from md5 import new as md5_hash |
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import sha |
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sha1 = sha |
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sha1_hash = sha.new |
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def _all(seq): |
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"""Returns True if all elements in the iterable are True.
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"""
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for _ in itertools.ifilterfalse(bool, seq): |
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return False |
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return True |
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def _any(seq): |
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"""Returns True if any element of the iterable are True.
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"""
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for _ in itertools.ifilter(bool, seq): |
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return True |
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return False |
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try:
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# pylint: disable=E0601
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# pylint: disable=W0622
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all = all
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except NameError: |
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all = _all |
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try:
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# pylint: disable=E0601
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# pylint: disable=W0622
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any = any
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except NameError: |
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any = _any |
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def partition(seq, pred=bool): # pylint: disable=W0622 |
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"""Partition a list in two, based on the given predicate.
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"""
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return (list(itertools.ifilter(pred, seq)), |
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list(itertools.ifilterfalse(pred, seq)))
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# Even though we're using Python's built-in "partial" function if available,
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# this one is always defined for testing.
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def _partial(func, *args, **keywords): # pylint: disable=W0622 |
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"""Decorator with partial application of arguments and keywords.
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This function was copied from Python's documentation.
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"""
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def newfunc(*fargs, **fkeywords): |
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newkeywords = keywords.copy() |
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newkeywords.update(fkeywords) |
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return func(*(args + fargs), **newkeywords) # pylint: disable=W0142 |
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newfunc.func = func |
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newfunc.args = args |
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newfunc.keywords = keywords |
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return newfunc
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if functools is None: |
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partial = _partial |
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else:
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partial = functools.partial |
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def TryToRoman(val, convert=True): |
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"""Try to convert a value to roman numerals
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If the roman module could be loaded convert the given value to a roman
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numeral. Gracefully fail back to leaving the value untouched.
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@type val: integer
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@param val: value to convert
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@type convert: boolean
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@param convert: if False, don't try conversion at all
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@rtype: string or typeof(val)
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@return: roman numeral for val, or val if conversion didn't succeed
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"""
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if roman is not None and convert: |
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try:
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return roman.toRoman(val)
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except roman.RomanError:
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return val
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else:
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return val
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def UniqueFrozenset(seq): |
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"""Makes C{frozenset} from sequence after checking for duplicate elements.
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@raise ValueError: When there are duplicate elements
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"""
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if isinstance(seq, (list, tuple)): |
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items = seq |
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else:
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items = list(seq)
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result = frozenset(items)
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if len(items) != len(result): |
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raise ValueError("Duplicate values found") |
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return result
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#: returns the first element of a list-like value
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fst = operator.itemgetter(0)
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#: returns the second element of a list-like value
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snd = operator.itemgetter(1)
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