def str2float(s):
s=s.split('.') s[1]=list(s[1]) s[1].reverse() def fn1(x,y): return x*10+y def fn2(x,y): return x/10+y

def digit(i) :
    digits = {'0': 0, '1': 1, '2': 2, '3': 3, '4': 4, '5': 5, '6': 6, '7': 7, '8': 8, '9': 9}
    return digits[i]

int_number=reduce(fn1,map(digit,s[0]))
float_number=reduce(fn2,map(digit,s[1]))
return int_number+float_number/10