Change the name of a key in dictionary

Question

I want to change the key of an entry in a Python dictionary.

Is there a straightforward way to do this?

Answer 1

Easily done in 2 steps:

dictionary[new_key] = dictionary[old_key] del dictionary[old_key] 

Or in 1 step:

dictionary[new_key] = dictionary.pop(old_key) 

which will raise KeyError if dictionary[old_key] is undefined. Note that this will delete dictionary[old_key].

>>> dictionary = { 1: 'one', 2:'two', 3:'three' } >>> dictionary['ONE'] = dictionary.pop(1) >>> dictionary {2: 'two', 3: 'three', 'ONE': 'one'} >>> dictionary['ONE'] = dictionary.pop(1) Traceback (most recent call last):   File "<input>", line 1, in <module> KeyError: 1 

Answer 2

if you want to change all the keys:

d = {'x':1, 'y':2, 'z':3} d1 = {'x':'a', 'y':'b', 'z':'c'}  In [10]: dict((d1[key], value) for (key, value) in d.items()) Out[10]: {'a': 1, 'b': 2, 'c': 3} 

if you want to change single key: You can go with any of the above suggestion.