Flip a Dictionary - Python?

Question

I am currently preparing for a python exam and one topic we are expected to understand is having to flip a dictionary in which values become the keys and the keys become values. I am confused as to what this asking and if someone could provide me with a basic example to see what it looks like I would greatly appreciate it.

I mean, this is one statement, there aren't that many things one can try. You either know how to do it or not... Better question would be if he's done any research on the issue yet. @not_a_robot — Markus Meskanen, Dec 04 '16 at 23:28
That's kind of implied... I just didn't want to give it away :) — blacksite, Dec 04 '16 at 23:32

score 4 · Answer 1 · edited Dec 05 '16 at 00:04

4

Simply write a dict comprehension expression and make it's key as value and values as key. For example:

>>> my_dict = {1: 2, 3: 4, 5: 6}
>>> {value: key for key, value in my_dict.items()}
{2: 1, 4: 3, 6: 5}

Note: Since, dict contains unique keys. In case you have same element as value for multiple keys in your original dict, you will loose related entries. For example:

# Same values     v           v
>>> my_dict = {1: 2, 3: 4, 5: 2}
>>> {value: key for key, value in my_dict.items()}
{2: 5, 4: 3}
#^ Only one entry of `2` as key

edited Dec 05 '16 at 00:04

Markus Meskanen

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answered Dec 04 '16 at 23:26

Moinuddin Quadri

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Why not add an example too, I've never heard of anyone complaining of too many examples! :) – Markus Meskanen Dec 04 '16 at 23:51

Flip a Dictionary - Python?

1 Answers1