使用 count() 函数的字符频率字典

Question

我需要一个函数的帮助，该函数将接受一个字符串和 return 一个字典，其中每个字母在字符串中出现了多少次使用 count() 函数

例如，对于“0010101”，它return是一个字典说：

The character frequency of "0010101" is {'0': 4, '1': 3}

def character_frequency(string):
  if len(string) == 0:
   return "{}"
# insert loop to determine the character counts in the string here

#test code for reference 
tests = ["", "0010101", "aaabbb"]

for x in tests:
  print('The character frequency of "' + x + '" is', character_frequency(x))

Answer 1

如果需要使用count()函数：

def character_frequency(string):
    return {char: string.count(char) for char in set(string)}

Answer 2

如果您愿意接受与 count 不同的实现，一种方法是使用 get，默认值为 0:

def character_frequency(string):
    freq = {}
    for c in string:
        freq[c] = freq.get(c, 0) + 1
    return freq

#test code for reference 
tests = ["", "0010101", "aaabbb"]

for x in tests:
    print('The character frequency of "' + x + '" is', character_frequency(x))

输出：

The character frequency of "" is {}
The character frequency of "0010101" is {'0': 4, '1': 3}
The character frequency of "aaabbb" is {'a': 3, 'b': 3}

Answer 3

txt = "I love apples, apple are my favorite fruit"
print(dict(zip(txt,[txt.count(char) for char in txt])))

计算字符串中每个字符的出现次数，并将它们存储为列表

将上面的列表与相应的字符合并并转换为字典

使用 count() 函数的字符频率字典

Character frequency dictionary using count() function

python

dictionary

loops

frequency