看了大神的，觉得我的太麻烦，汗，但是坚持打卡

char2float= {'0': 0.0, '1': 1, '2': 2, '3': 3, '4': 4, '5': 5, '6': 6, '7': 7, '8': 8, '9': 9}


def strtfloat(s):
    s = map(lambda ch: char2float[ch], s)
    return reduce(lambda x, y: x * 10 + y, s)


def strtx(s):
    s = map(lambda ch: char2float[ch], s)
    return reduce(lambda x, y: x / 10 + y, s)


def str2float(s):
    s = str(s)
    s = s.split('.'）
    s1 = strtfloat(s[0])
    tmp = s[1][::-1]
    s2 = strtx(tmp)
    return s1 + s2 / 10

s = input("string")
a = str2float(s)
print(a)``