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""" |
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For Python < 2.7.2. total_ordering in versions prior to 2.7.2 is buggy. |
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See http://bugs.python.org/issue10042 for details. For these versions use |
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code borrowed from Python 2.7.3. |
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From django.utils. |
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""" |
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import sys |
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if sys.version_info >= (2, 7, 2): |
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from functools import total_ordering |
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else: |
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def total_ordering(cls): |
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"""Class decorator that fills in missing ordering methods""" |
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convert = { |
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'__lt__': [('__gt__', lambda self, other: not (self < other or self == other)), |
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('__le__', lambda self, other: self < other or self == other), |
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('__ge__', lambda self, other: not self < other)], |
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'__le__': [('__ge__', lambda self, other: not self <= other or self == other), |
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('__lt__', lambda self, other: self <= other and not self == other), |
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('__gt__', lambda self, other: not self <= other)], |
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'__gt__': [('__lt__', lambda self, other: not (self > other or self == other)), |
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('__ge__', lambda self, other: self > other or self == other), |
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('__le__', lambda self, other: not self > other)], |
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'__ge__': [('__le__', lambda self, other: (not self >= other) or self == other), |
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('__gt__', lambda self, other: self >= other and not self == other), |
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('__lt__', lambda self, other: not self >= other)] |
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} |
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roots = set(dir(cls)) & set(convert) |
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if not roots: |
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raise ValueError('must define at least one ordering operation: < > <= >=') |
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root = max(roots) |
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for opname, opfunc in convert[root]: |
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if opname not in roots: |
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opfunc.__name__ = opname |
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opfunc.__doc__ = getattr(int, opname).__doc__ |
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setattr(cls, opname, opfunc) |
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return cls |
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