字符串反转特殊字符保持位置不变（python）

given a string,that contains special character together with alphabets(
“a” to “z” and “A” to “Z”), reverse the string in a way that special characters are not affected
思路： 把反转后的字符回填到原来的字符串中

def reversed_char(string):
    strs = string[::-1]
    length = len(strs)
    #mark = "".join((chr(i) for i in range(97, 123))) + "".join(chr(i) for i in range(65, 91))
    mark = "".join(tuple(chr(i) for i in range(97,123))+ tuple(chr(i) for i in range(65,91)))
    temp = list(string)
    res = "" # 保存反转后字母
    for i in range(length):
        if strs[i] not in mark:
            continue
        res += strs[i]

    # 把原始字符串对应位置的字母换成"_"
    for i in range(length):
        if string[i] in mark:
            temp[i] = "-"

    # 逆序字母的回填
    index = 0
    for item in res:
        while temp[index] != "-":
            index += 1
        temp[index] = item
        index += 1
    print(f'output: str = {"".join(temp)}')

if __name__ == '__main__':
    reversed_char("Ab,c,de!$")

– 优化一下

def reversed_char(string):
    strs = string[::-1]
    length = len(strs)
    #mark = "".join((chr(i) for i in range(97, 123))) + "".join(chr(i) for i in range(65, 91))
    mark = "".join(tuple(chr(i) for i in range(97,123))+ tuple(chr(i) for i in range(65,91)))
    temp = list(string)
    res = "" # 保存反转后字母
    for i in range(length):
        if strs[i] not in mark:
            continue
        res += strs[i]

    # 把原始字符串对应位置的字母换成"_"
    # for i in range(length):
    #     if string[i] in mark:
    #         temp[i] = "-"

    # 逆序字母的回填
    index = 0
    for i in res:
        while temp[index] not in mark: # 说明 ",$"不替换
            index += 1
        temp[index] = i
        index += 1
    print(f'output: str = {"".join(temp)}')