Package ganeti :: Module compat
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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    # Yes, these don't always exist, that's why we're testing 
 49    # Yes, we're not using the imports in this module. 
 50    from hashlib import md5 as md5_hash # pylint: disable=W0611,E0611,F0401 
 51    from hashlib import sha1 as sha1_hash # pylint: disable=W0611,E0611,F0401 
 52    # this additional version is needed for compatibility with the hmac module 
 53    sha1 = sha1_hash 
 54  except ImportError: 
 55    from md5 import new as md5_hash 
 56    import sha 
 57    sha1 = sha 
 58    sha1_hash = sha.new 
 59   
 60   
61 -def _all(seq):
62 """Returns True if all elements in the iterable are True. 63 64 """ 65 for _ in itertools.ifilterfalse(bool, seq): 66 return False 67 return True
68 69
70 -def _any(seq):
71 """Returns True if any element of the iterable are True. 72 73 """ 74 for _ in itertools.ifilter(bool, seq): 75 return True 76 return False
77 78 79 try: 80 # pylint: disable=E0601 81 # pylint: disable=W0622 82 all = all 83 except NameError: 84 all = _all 85 86 try: 87 # pylint: disable=E0601 88 # pylint: disable=W0622 89 any = any 90 except NameError: 91 any = _any 92 93
94 -def partition(seq, pred=bool): # pylint: disable=W0622
95 """Partition a list in two, based on the given predicate. 96 97 """ 98 return (list(itertools.ifilter(pred, seq)), 99 list(itertools.ifilterfalse(pred, seq))) 100 101 102 # Even though we're using Python's built-in "partial" function if available, 103 # this one is always defined for testing.
104 -def _partial(func, *args, **keywords): # pylint: disable=W0622
105 """Decorator with partial application of arguments and keywords. 106 107 This function was copied from Python's documentation. 108 109 """ 110 def newfunc(*fargs, **fkeywords): 111 newkeywords = keywords.copy() 112 newkeywords.update(fkeywords) 113 return func(*(args + fargs), **newkeywords) # pylint: disable=W0142 114 115 newfunc.func = func 116 newfunc.args = args 117 newfunc.keywords = keywords 118 return newfunc 119 120 121 if functools is None: 122 partial = _partial 123 else: 124 partial = functools.partial 125 126
127 -def TryToRoman(val, convert=True):
128 """Try to convert a value to roman numerals 129 130 If the roman module could be loaded convert the given value to a roman 131 numeral. Gracefully fail back to leaving the value untouched. 132 133 @type val: integer 134 @param val: value to convert 135 @type convert: boolean 136 @param convert: if False, don't try conversion at all 137 @rtype: string or typeof(val) 138 @return: roman numeral for val, or val if conversion didn't succeed 139 140 """ 141 if roman is not None and convert: 142 try: 143 return roman.toRoman(val) 144 except roman.RomanError: 145 return val 146 else: 147 return val
148 149
150 -def UniqueFrozenset(seq):
151 """Makes C{frozenset} from sequence after checking for duplicate elements. 152 153 @raise ValueError: When there are duplicate elements 154 155 """ 156 if isinstance(seq, (list, tuple)): 157 items = seq 158 else: 159 items = list(seq) 160 161 result = frozenset(items) 162 163 if len(items) != len(result): 164 raise ValueError("Duplicate values found") 165 166 return result
167 168 169 #: returns the first element of a list-like value 170 fst = operator.itemgetter(0) 171 172 #: returns the second element of a list-like value 173 snd = operator.itemgetter(1) 174