Source Code for Module ganeti.compat

  1  # 
  2  # 
  3   
  4  # Copyright (C) 2010, 2011 Google Inc. 
  5  # 
  6  # This program is free software; you can redistribute it and/or modify 
  7  # it under the terms of the GNU General Public License as published by 
  8  # the Free Software Foundation; either version 2 of the License, or 
  9  # (at your option) any later version. 
 10  # 
 11  # This program is distributed in the hope that it will be useful, but 
 12  # WITHOUT ANY WARRANTY; without even the implied warranty of 
 13  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU 
 14  # General Public License for more details. 
 15  # 
 16  # You should have received a copy of the GNU General Public License 
 17  # along with this program; if not, write to the Free Software 
 18  # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 
 19  # 02110-1301, USA. 
 20   
 21   
 22  """Module containing backported language/library functionality. 
 23   
 24  """ 
 25   
 26  import itertools 
 27  import operator 
 28   
 29  try: 
 30    # pylint: disable=F0401 
 31    import functools 
 32  except ImportError: 
 33    functools = None 
 34   
 35  try: 
 36    # pylint: disable=F0401 
 37    import roman 
 38  except ImportError: 
 39    roman = None 
 40   
 41   
 42  # compat.md5_hash and compat.sha1_hash can be called to generate and md5 and a 
 43  # sha1 hashing modules, under python 2.4, 2.5 and 2.6, even though some changes 
 44  # went on. compat.sha1 is python-version specific and is used for python 
 45  # modules (hmac, for example) which have changed their behavior as well from 
 46  # one version to the other. 
 47  try: 
 48    # pylint: disable=F0401 
 49    # Yes, we're not using the imports in this module. 
 50    # pylint: disable=W0611 
 51    from hashlib import md5 as md5_hash 
 52    from hashlib import sha1 as sha1_hash 
 53    # this additional version is needed for compatibility with the hmac module 
 54    sha1 = sha1_hash 
 55  except ImportError: 
 56    from md5 import new as md5_hash 
 57    import sha 
 58    sha1 = sha 
 59    sha1_hash = sha.new 
 60   
 61   
 62 -def _all(seq): 
 63    """Returns True if all elements in the iterable are True. 
 64   
 65    """ 
 66    for _ in itertools.ifilterfalse(bool, seq): 
 67      return False 
 68    return True 
 69   
 70   
 71 -def _any(seq): 
 72    """Returns True if any element of the iterable are True. 
 73   
 74    """ 
 75    for _ in itertools.ifilter(bool, seq): 
 76      return True 
 77    return False 
 78   
 79   
 80  try: 
 81    # pylint: disable=E0601 
 82    # pylint: disable=W0622 
 83    all = all 
 84  except NameError: 
 85    all = _all 
 86   
 87  try: 
 88    # pylint: disable=E0601 
 89    # pylint: disable=W0622 
 90    any = any 
 91  except NameError: 
 92    any = _any 
 93   
 94   
 95 -def partition(seq, pred=bool): # pylint: disable=W0622 
 96    """Partition a list in two, based on the given predicate. 
 97   
 98    """ 
 99    return (list(itertools.ifilter(pred, seq)), 
100            list(itertools.ifilterfalse(pred, seq))) 
101   
102   
103  # Even though we're using Python's built-in "partial" function if available, 
104  # this one is always defined for testing. 
105 -def _partial(func, *args, **keywords): # pylint: disable=W0622 
106    """Decorator with partial application of arguments and keywords. 
107   
108    This function was copied from Python's documentation. 
109   
110    """ 
111    def newfunc(*fargs, **fkeywords): 
112      newkeywords = keywords.copy() 
113      newkeywords.update(fkeywords) 
114      return func(*(args + fargs), **newkeywords) # pylint: disable=W0142 
115   
116    newfunc.func = func 
117    newfunc.args = args 
118    newfunc.keywords = keywords 
119    return newfunc 
120   
121   
122  if functools is None: 
123    partial = _partial 
124  else: 
125    partial = functools.partial 
126   
127   
128 -def TryToRoman(val, convert=True): 
129    """Try to convert a value to roman numerals 
130   
131    If the roman module could be loaded convert the given value to a roman 
132    numeral. Gracefully fail back to leaving the value untouched. 
133   
134    @type val: integer 
135    @param val: value to convert 
136    @type convert: boolean 
137    @param convert: if False, don't try conversion at all 
138    @rtype: string or typeof(val) 
139    @return: roman numeral for val, or val if conversion didn't succeed 
140   
141    """ 
142    if roman is not None and convert: 
143      try: 
144        return roman.toRoman(val) 
145      except roman.RomanError: 
146        return val 
147    else: 
148      return val 
149   
150  #: returns the first element of a list-like value 
151  fst = operator.itemgetter(0) 
152   
153  #: returns the second element of a list-like value 
154  snd = operator.itemgetter(1) 
155