计算字符串中某个字符出现的次数

如何计算字符串中字符出现的次数?

如。“a”在“Mary had a little lamb”中出现了4次。

当前回答

python - 3. x:

"aabc".count("a")

Str.count (sub[， start[， end]]) 返回子字符串sub在范围[start, end]中不重叠出现的次数。可选参数start和end被解释为片表示法。

其他回答

a = 'have a nice day'
symbol = 'abcdefghijklmnopqrstuvwxyz'
for key in symbol:
    print(key, a.count(key))

a = "I walked today,"
c=['d','e','f']
count=0
for i in a:
    if str(i) in c:
        count+=1

print(count)

Str.count (sub[， start[， end]]) 返回子字符串sub在范围[start, end]中不重叠出现的次数。可选参数start和end被解释为片表示法。

>>> sentence = 'Mary had a little lamb'
>>> sentence.count('a')
4

myString.count('a');

更多信息请点击这里

正则表达式?

import re
my_string = "Mary had a little lamb"
len(re.findall("a", my_string))

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