# -*- coding: utf-8 -*- 

from functools import reduce

normalize = lambda n : str(n).title(); # 使用自带的title()方法

def prod(L):
    return reduce(lambda x,y:x*y,L) # lambda表达式计算乘积

print('3 * 5 * 7 * 9 =', prod([3, 5, 7, 9]))

def str2float(s):
    try:
        isNeg,f = -int(s[0]=='-') or 1,list(map(lambda st: reduce(lambda x,y:int(x != '-' and x or 0)*10+int(y[0]),st),s.split('.')))
        return (int(f[0])+int(f[1])/pow(10,len(s)-s.find('.')-1)) * isNeg
    except ValueError as err: print('Failed: Invalid String\n'+err.__str__());
    except Exception as e: print(e);

print('str2float(\'123.456\') =', str2float('123.456'))