Python 统计一个英文字符串中每个字符出现的次数

Python 统计一个英文字符串中每个字符出现的次数 三种方法

方法一

定义字符串转化为list函数strchls

def strchls (str):
    list = []  # 集合
    i = 0
    for w in str:
        # print(w)
        if w != ' ':
            list.append(w)
    return list

定义list 转化为字典序列，并把字符作为key(不重复）

def countw(list):
    count_word = {}
    for w in list:
        # j = 1
        if w not in count_word.keys():
            count_word[w] = 1  # 编号 w:j
        else:
            count_word[w] += 1  # 编号 w:j
    return count_word

函数调用

str = 'how are you'
ls = strchls (str)
print(countw(ls))

方法二

#去空格，转化为list，然后再转化为字典即可

str =  'how are you'
list = []
list2 = []
dict={}
i= 0
for w in str:
    if w!=' ':
        list.append(w)
# print(list)
for w in list:
    c = list.count(w)
    dict[w] = c
print(dict)

方法三

直接去空格，转化为字典，利用字典的key值唯一

str =  'how are you'
dict = {}
for w1 in str:
    if w1 != ' ':
        for w1 in list:
            c = list.count(w1)
            dict[w1] = c
print(dict)