CODEWITHSUNDEEP
pythonpermutationpython-itertools
Narabhut
Narabhut

Reputation: 837

Permutations of dictionary in python

I have a dictionary like this - 

{'A': 0, 'B': 0, 'C': 0, 'D': 4}

I want to generate a list like this - 

[{'A': 1, 'B': 0, 'C': 0, 'D': 4},
 {'A': 0, 'B': 1, 'C': 0, 'D': 4},
 {'A': 0, 'B': 0, 'C': 1, 'D': 4},
 {'A': 0, 'B': 0, 'C': 0, 'D': 5}]

What is the most pythonic way to do this?

Upvotes: 3

Views: 1928

Answers (1)

thefourtheye
thefourtheye

Reputation: 239653

You can use list comprehension and dictionary comprehension together, like this

d = {'A': 0, 'B': 0, 'C': 0, 'D': 4}
print [{key1: d[key1] + (key1 == key) for key1 in d} for key in d]

Output

[{'A': 1, 'B': 0, 'C': 0, 'D': 4},
 {'A': 0, 'B': 0, 'C': 1, 'D': 4},
 {'A': 0, 'B': 1, 'C': 0, 'D': 4},
 {'A': 0, 'B': 0, 'C': 0, 'D': 5}]

The idea is to generate a new dictionary for each key, and when the key matches the key of the dictionary being constructed with dictionary comprehension, then add 1 to it. (key1 == key) will evaluate to 1 only when both the keys match, otherwise it will be zero.

Upvotes: 5

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