Mercurial > hg > config
annotate python/mutable_defaults.py @ 114:9b193312ceba
actually, we *do* want to write into the dict!
author | Jeff Hammel <jhammel@mozilla.com> |
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date | Thu, 02 Dec 2010 16:25:26 -0800 |
parents | 70544c7406e2 |
children | 434c65593612 |
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70544c7406e2
add illustration program for mutable arguments, since this comes up a bunch
Jeff Hammel <jhammel@mozilla.com>
parents:
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changeset
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1 #!/usr/bin/env python |
70544c7406e2
add illustration program for mutable arguments, since this comes up a bunch
Jeff Hammel <jhammel@mozilla.com>
parents:
diff
changeset
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2 |
70544c7406e2
add illustration program for mutable arguments, since this comes up a bunch
Jeff Hammel <jhammel@mozilla.com>
parents:
diff
changeset
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3 class Foo(object): |
70544c7406e2
add illustration program for mutable arguments, since this comes up a bunch
Jeff Hammel <jhammel@mozilla.com>
parents:
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changeset
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4 def __init__(self, mutable=['default']): |
70544c7406e2
add illustration program for mutable arguments, since this comes up a bunch
Jeff Hammel <jhammel@mozilla.com>
parents:
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changeset
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5 self.foo = mutable |
70544c7406e2
add illustration program for mutable arguments, since this comes up a bunch
Jeff Hammel <jhammel@mozilla.com>
parents:
diff
changeset
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6 self.foo.append(1) |
70544c7406e2
add illustration program for mutable arguments, since this comes up a bunch
Jeff Hammel <jhammel@mozilla.com>
parents:
diff
changeset
|
7 |
70544c7406e2
add illustration program for mutable arguments, since this comes up a bunch
Jeff Hammel <jhammel@mozilla.com>
parents:
diff
changeset
|
8 if __name__ == '__main__': |
70544c7406e2
add illustration program for mutable arguments, since this comes up a bunch
Jeff Hammel <jhammel@mozilla.com>
parents:
diff
changeset
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9 bar = Foo() |
70544c7406e2
add illustration program for mutable arguments, since this comes up a bunch
Jeff Hammel <jhammel@mozilla.com>
parents:
diff
changeset
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10 print len(bar.foo) |
70544c7406e2
add illustration program for mutable arguments, since this comes up a bunch
Jeff Hammel <jhammel@mozilla.com>
parents:
diff
changeset
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11 fleem = Foo() |
70544c7406e2
add illustration program for mutable arguments, since this comes up a bunch
Jeff Hammel <jhammel@mozilla.com>
parents:
diff
changeset
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12 print len(fleem.foo) |
70544c7406e2
add illustration program for mutable arguments, since this comes up a bunch
Jeff Hammel <jhammel@mozilla.com>
parents:
diff
changeset
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13 assert len(fleem.foo) == 2, "Don't use default mutable arguments!" |