Inverting the original dict with non-unique values can be done cleaner (without the explicit two line for loop and IMO easier to read) using a defaultdict:
>>>fromcollectionsimportdefaultdict>>># Original dict >>>my_dict={'Izuku Midoriya':'One for All','Katsuki Bakugo':'Explosion','All Might':'One for All','Ochaco Uraraka':'Zero Gravity'}>>>my_dict_inverted=defaultdict(list)>>>[my_dict_inverted[v].append(k)fork,vinmy_dict.items()]>>>my_dict_inverteddefaultdict(<class'list'>, {'OneforAll': ['IzukuMidoriya', 'AllMight'], 'Explosion': ['KatsukiBakugo'], 'ZeroGravity': ['OchacoUraraka']})
Or to make it more intuitive denote the comprehension using a dict since that is what we are applying the operation to:
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Great addition! I would prefer to maintain the dict type and leave out any extraneous imports, but this gets the job done and is probably less error prone.
It's part of the standard library and it's still a dict so you can use any it like a normal dict, e.g. my_dict_inverted['One for All'] as well as all methods from a normal dict like keys(), values() and items().
I teach computer science to undergrads and write for The Renegade Coder. I'm most likely taking care of my daughter, watching the Penguins, or reading manga.
Location
Columbus, Ohio
Education
B.S. in CE from CWRU 2016; M.S. in CSE from OSU 2020; PhD in EED from OSU 2024
Hi again! I'm in the process of updating this article, and I just realized that this answer has a minor problem. We're using a dictionary comprehension in a bad way. We're updating some external dictionary while the comprehension will also generate a dictionary (in this case, {None}). I believe that's considered bad practice, so I've added a note in the original article.
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Inverting the original dict with non-unique values can be done cleaner (without the explicit two line
forloop and IMO easier to read) using adefaultdict:Or to make it more intuitive denote the comprehension using a
dictsince that is what we are applying the operation to:Great addition! I would prefer to maintain the dict type and leave out any extraneous imports, but this gets the job done and is probably less error prone.
Mind if I add it to the list?
Go ahead :)
It's part of the standard library and it's still a dict so you can use any it like a normal dict, e.g.
my_dict_inverted['One for All']as well as all methods from a normal dict likekeys(),values()anditems().Hi again! I'm in the process of updating this article, and I just realized that this answer has a minor problem. We're using a dictionary comprehension in a bad way. We're updating some external dictionary while the comprehension will also generate a dictionary (in this case,
{None}). I believe that's considered bad practice, so I've added a note in the original article.