Getting the top length of a key in Python [duplicate]

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Closed 8 years ago.

Possible Duplicate:
Find longest (string) key in dictionary

Without folding. Example:

from functools import reduce
dict = {'t1': 'test1', 'test2': 't2'}
print(len(reduce(lambda x, y: x if len(x) >= len(y) else y, dict.keys())))

Is there any way to get the longest key's length in a a dictionary (preferably in one line)? There's nothing wrong with folding but I'm just interested if there's another way to do it in Python 3.

Answer 1

You can simply do

max(map(len, my_dict))

This will take the lengths of all keys and extract the maximum of these lengths.

To get the longest key itself, use

max(my_dict, key=len)