Python For Not In

Question

I have a dict test declared:

test = {'test1': 1, 'test2': 2, 'test3': 3}

And I want to make a copy of test filtering out specific keys that may or may not exist.

I tried the following:

test_copy = {k: test[k] for k not in ('test3', 'test4')}

However Python does not seem to like for not in loops. Is there any way to do this nicely in one line?

I do not believe this question is a duplicate of List comprehension with if statement because I was searching for more than a few minutes specifically for dicts.

Hmm, I closed this, but in retrospect it might not be the correct duplicate to close it against... — Andy Hayden, Nov 05 '15 at 00:16
I am relatively new to python but have experience with other languages. I feel like my question is specific to my particular problem rather than the umbrella questions other people had that might not come up in searches. — Mocking, Nov 05 '15 at 00:25

score 6 · Accepted Answer · edited Nov 05 '15 at 00:13

6

The dictionary comprehension test_copy = {k: test[k] for k in test if k not in EXCLUDED_KEYS} will accomplish the copying.

edited Nov 05 '15 at 00:13

BrenBarn

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answered Nov 05 '15 at 00:13

pppery

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Thank you! I tried almost the same thing without the 'in test'. – Mocking Nov 05 '15 at 00:15

score 4 · Answer 2 · answered Nov 05 '15 at 00:13

4

You need to state the "not in" in the conditional:

test_copy = {k: test[k] for k in test if k not in ('test3', 'test4')}

answered Nov 05 '15 at 00:13

Andy Hayden

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Python For Not In

2 Answers2