计数字母出现Python

Question

我试图计算字母出现并打印出来.这是我到目前为止:

def histogram(L):
    d = {}
    for x in L:
      for letter in x:
        if letter in d:
          d[letter] += 1
        else:
          d[letter] = 1
    for i in range(len(d)):
      print('{} | {}'.format(d, d[i])) # GETTING ERRORS ON THIS LINE
    return d
histogram(open('cipher.txt'))

出于某种原因,我在这条线上遇到错误.我该如何正确打印？

编辑:解决我的Martijn!道具!但有谁知道如何按字母顺序对字典进行排序？

Answer 1

d是字典,而不是列表.循环键:

for key in d:
    print('{} | {}'.format(key, d[key]))

或者你会得到KeyError例外.

你可能对这collections.Counter()堂课感兴趣; 这是一个计数词典:

from collections import Counter

def histogram(L):
    d = Counter(letter for line in L for letter in x)
    for letter in d:
        print('{} | {}'.format(letter, d[letter]))
    return d