题解 | 计算某字符出现次数

import sys
import re

def count(input_str,input_letter):
    for v in input_str:
        if re.match(r'[a-zA-Z0-9\s]$',v):
            continue
        else:
            return ("有非数字或字母的字符")

    count_num=0
    for v in input_str:
        if v.upper() == input_letter.upper():
            count_num +=1

    return count_num

if __name__ == "__main__":
    input_str=input()
    input_letter= input()
    number= count(input_str,input_letter)
    print(number)