Switching Two Values in Dictionary, Keeping Keys Constant

Question

What would be the most efficient way to switch say two values in a dictionary, so that two keys would be mapping to two different values?

score 3 · Accepted Answer · edited May 23 '17 at 11:49

3

Use tuple assignment:

d['bar'], d['foo'] = d['foo'], d['bar']

This simply swaps the values. The Python compiler optimizes for such cases, and this doesn't require any frame stack pushes (provided d doesn't implement __getitem__ and / or __setitem__ hooks in Python code).

edited May 23 '17 at 11:49

Community

1
1

answered Apr 26 '14 at 15:11

Martijn Pieters

1,048,767
296
4,058
3,343

score 3 · Answer 2 · answered Apr 26 '14 at 15:12

3

The same way you would swap any other values:

my_dict[key0], my_dict[key1] = my_dict[key1], my_dict[key0]

answered Apr 26 '14 at 15:12

juanchopanza

223,364
34
402
480

Switching Two Values in Dictionary, Keeping Keys Constant

2 Answers2