Mercurial > hg > config
comparison python/mutable_defaults.py @ 91:70544c7406e2
add illustration program for mutable arguments, since this comes up a bunch
author | Jeff Hammel <jhammel@mozilla.com> |
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date | Tue, 21 Sep 2010 08:30:19 -0700 |
parents | |
children | 434c65593612 |
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90:6d09c2a8e5e9 | 91:70544c7406e2 |
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1 #!/usr/bin/env python | |
2 | |
3 class Foo(object): | |
4 def __init__(self, mutable=['default']): | |
5 self.foo = mutable | |
6 self.foo.append(1) | |
7 | |
8 if __name__ == '__main__': | |
9 bar = Foo() | |
10 print len(bar.foo) | |
11 fleem = Foo() | |
12 print len(fleem.foo) | |
13 assert len(fleem.foo) == 2, "Don't use default mutable arguments!" |