72 lines
1.9 KiB
Python
72 lines
1.9 KiB
Python
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try:
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reversed = reversed
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except NameError:
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def reversed(sequence):
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"""reversed(sequence) -> reverse iterator over values of the sequence
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Return a reverse iterator
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"""
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if hasattr(sequence, '__reversed__'):
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return sequence.__reversed__()
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if not hasattr(sequence, '__getitem__'):
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raise TypeError("argument to reversed() must be a sequence")
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return reversed_iterator(sequence)
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class reversed_iterator(object):
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def __init__(self, seq):
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self.seq = seq
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self.remaining = len(seq)
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def __iter__(self):
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return self
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def next(self):
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i = self.remaining
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if i > 0:
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i -= 1
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item = self.seq[i]
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self.remaining = i
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return item
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raise StopIteration
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def __length_hint__(self):
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return self.remaining
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try:
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sorted = sorted
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except NameError:
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builtin_cmp = cmp # need to use cmp as keyword arg
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def sorted(iterable, cmp=None, key=None, reverse=0):
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use_cmp = None
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if key is not None:
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if cmp is None:
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def use_cmp(x, y):
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return builtin_cmp(x[0], y[0])
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else:
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def use_cmp(x, y):
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return cmp(x[0], y[0])
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l = [(key(element), element) for element in iterable]
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else:
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if cmp is not None:
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use_cmp = cmp
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l = list(iterable)
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if use_cmp is not None:
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l.sort(use_cmp)
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else:
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l.sort()
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if reverse:
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l.reverse()
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if key is not None:
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return [element for (_, element) in l]
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return l
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try:
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set, frozenset = set, frozenset
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except NameError:
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from sets import set, frozenset
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# pass through
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enumerate = enumerate
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