view python/example/mutable_defaults.py @ 837:5ba219864529

add example program
author Jeff Hammel <k0scist@gmail.com>
date Mon, 27 Mar 2017 14:05:29 -0700
parents d6f659169b49
children
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#!/usr/bin/env python

# see also: http://www.daniweb.com/software-development/python/threads/66697

class Foo(object):
  def __init__(self, mutable=['default']):
    self.foo = mutable
    self.foo.append(1)

if __name__ == '__main__':
  bar = Foo()
  print len(bar.foo)
  fleem = Foo()
  print len(fleem.foo)
  assert len(fleem.foo) == 2, "Don't use default mutable arguments!"