python - 输入一个句子并计算每个字母？

Question

所以基本上我需要程序来计算每个字母在句子中使用了多少次。 我唯一发现的是这个，它很丑:

from collections import Counter
str = "Mary had a little lamb"
counter = Counter(str)
print counter['a']
print counter['b']
print counter['c']
print counter['d']
print counter['e']
print counter['f']
#etc to z

有没有更简单的方法来做到这一点？？？？

Answer 1

假设我理解你:

>>> from collections import Counter
>>> from string import ascii_lowercase
>>> s = "Mary had a little lamb"
>>> counts = Counter(s.lower())
>>> for letter in ascii_lowercase:
...     print letter, counts[letter]
...     
a 4
b 1
c 0
[...]
x 0
y 1
z 0

请注意，我将字符串小写，以便 m 会给出 2；如果你不想这样，删除 .lower() 并改用 string.ascii_letters。