python/lib/django_1_4/django/utils/itercompat.py

   1 """
   2 Providing iterator functions that are not in all version of Python we support.
   3 Where possible, we try to use the system-native version and only fall back to
   4 these implementations if necessary.
   5 """
   6
   7 import __builtin__
   8 import itertools
   9 import warnings
  10
  11 # Fallback for Python 2.5
  12 def product(*args, **kwds):
  13     """
  14     Taken from http://docs.python.org/library/itertools.html#itertools.product
  15     """
  16     # product('ABCD', 'xy') --> Ax Ay Bx By Cx Cy Dx Dy
  17     # product(range(2), repeat=3) --> 000 001 010 011 100 101 110 111
  18     pools = map(tuple, args) * kwds.get('repeat', 1)
  19     result = [[]]
  20     for pool in pools:
  21         result = [x+[y] for x in result for y in pool]
  22     for prod in result:
  23         yield tuple(prod)
  24
  25 if hasattr(itertools, 'product'):
  26     product = itertools.product
  27
  28 def is_iterable(x):
  29     "A implementation independent way of checking for iterables"
  30     try:
  31         iter(x)
  32     except TypeError:
  33         return False
  34     else:
  35         return True
  36
  37 def all(iterable):
  38     warnings.warn("django.utils.itercompat.all is deprecated; use the native version instead",
  39                   PendingDeprecationWarning)
  40     return __builtin__.all(iterable)
  41
  42 def any(iterable):
  43     warnings.warn("django.utils.itercompat.any is deprecated; use the native version instead",
  44                   PendingDeprecationWarning)
  45     return __builtin__.any(iterable)