查找字典中的最長（字符串）鍵

Question

此問題與Python - Find longest (most words) key in dictionary類似 - 但我需要純字符數。

例輸入：

d = {'group 1': 1, 'group 1000': 0} 

輸出：

10 

Answer 1

替代，這是一樣快@ jamylak的解決方案和更Python：

from itertools import imap 
max(imap(len, d)) 

查看產品比較：

$ python -m timeit -s "d = {'group 1': 1, 'group 1000': 0}" "len(max(d,key=len))" 
1000000 loops, best of 3: 0.538 usec per loop 

$ python -m timeit -s "d = {'group 1': 1, 'group 1000': 0}" "max(len(x) for x in d)" 
1000000 loops, best of 3: 0.7 usec per loop 

$ python -m timeit -s "d = {'group 1': 1, 'group 1000': 0}; from itertools import imap" \ 
    "max(imap(len, d))" 
1000000 loops, best of 3: 0.557 usec per loop 

Answer 2

>>> d = {'group 1': 1, 'group 1000': 0} 
>>> len(max(d, key=len)) 
10 

該解決方案是最快的，但我更喜歡通過@eumiro和@ ms4py的解決方案，因爲它們不重複len功能兩次，更pythonic imo。

Answer 3

>>> max(len(x) for x in d) 

或

>>> max(map(len, d))