Finding all the keys with the same value in a Python dictionary

Question

Let's say I have a dictionary:

dict1 = {"Jim": "y", "Bob": "y", "Ravioli": "n"}  # etc.

I want to print out all the keys with the value "y" (i.e: "Jim", "Bob"). How do I achieve this (in the simplest way possible)?

It seems like your actual problem is your dictionary is backwards, with `{'y': ['Jim', ...], ...}` you can get your answer in `O(1)`. — jonrsharpe, Feb 24 '17 at 12:44
@RomanPerekhrest that answer only finds one of the keys with a certain value — Cobie Fisher, Feb 24 '17 at 12:45
The top answer in the link provided returns all the values (and not just one). — B. Decoster, Feb 24 '17 at 15:44

score 37 · Accepted Answer · edited Dec 26 '22 at 23:14

37

You can use this:

[k for k, v in dict1.items() if v == 'y']

Result:

['Bob', 'Jim']

edited Dec 26 '22 at 23:14

mkrieger1

answered Feb 24 '17 at 12:37

Rahul K P

1

"And please don't use dict as a variable name." hahah I know, that was just a theoretical question for clarity – Cobie Fisher Feb 24 '17 at 12:46
How will it be used for multiple outputs? i.e. if I have to print for v == 'y' and lets assume v == 'x' and so on – Srijan Chaudhary Apr 04 '19 at 00:08
1

@SrijanChaudhary Then you can change the if condition like this `if v in ('x','y','z')` – Rahul K P Apr 04 '19 at 05:35
9

@RahulKP but this will be a very inefficient way to do, and it is somewhat doing a hard code, what if we don't know all the values? – Srijan Chaudhary Apr 05 '19 at 03:25

1 Answers1