32 lines
593 B
Python
32 lines
593 B
Python
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from contextlib import contextmanager
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__all__ = [
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'reversed',
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]
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@contextmanager
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def reversed(G):
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"""A context manager for temporarily reversing a directed graph in place.
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This is a no-op for undirected graphs.
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Parameters
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----------
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G : graph
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A NetworkX graph.
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"""
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directed = G.is_directed()
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if directed:
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G._pred, G._succ = G._succ, G._pred
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G._adj = G._succ
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try:
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yield
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finally:
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if directed:
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# Reverse the reverse.
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G._pred, G._succ = G._succ, G._pred
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G._adj = G._succ
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