Wiki

Python dict() copy

$ python
Python 2.7.8 (default, Oct 14 2014, 11:42:50) 
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> a={'a':{'b':'c'},'d':0}
>>> a
{'a': {'b': 'c'}, 'd': 0}
>>> b=a
>>> c=dict(a)
>>> b
{'a': {'b': 'c'}, 'd': 0}
>>> c
{'a': {'b': 'c'}, 'd': 0}
>>> c['d']=1
>>> c
{'a': {'b': 'c'}, 'd': 1}
>>> a
{'a': {'b': 'c'}, 'd': 0}
>>> c['a']['b']='f'
>>> c
{'a': {'b': 'f'}, 'd': 1}
>>> a
{'a': {'b': 'f'}, 'd': 0}
>>> import copy
>>> c=copy.deepcopy(a)
>>> a
{'a': {'b': 'f'}, 'd': 0}
>>> c
{'a': {'b': 'f'}, 'd': 0}
>>> c['d']=1
>>> c
{'a': {'b': 'f'}, 'd': 1}
>>> a
{'a': {'b': 'f'}, 'd': 0}
>>> c['a']['b']='f'
>>> c['a']['b']='g'
>>> c
{'a': {'b': 'g'}, 'd': 1}
>>> a
{'a': {'b': 'f'}, 'd': 0}
>>> 
Permalink. First published on Wed 24 December 2014.