n=[i for i,v in enumerate(s) if v=='.']
from functools import reduce
def char2num(s):
    return {'0': 0, '1': 1, '2': 2, '3': 3, '4': 4, '5': 5, '6': 6, '7': 7, '8': 8, '9': 9}[s]
def str2int(s):
    return reduce(lambda x, y: x * 10 + y, map(char2num, s))
return str2int(s[:n[0]])+str2int(s[n[0]+1:])*0.1**(n[0])