如何判断一个整数是偶数还是奇数[关闭]

def is_odd(num):
    # Return True or False, depending on if the input number is odd. 
    # Odd numbers are 1, 3, 5, 7, and so on. 
    # Even numbers are 0, 2, 4, 6, and so on. 

我想知道你会从这里做什么来得到这些答案。

def is_odd(num):
    return num & 0x1

它不是最具可读性的，但速度很快：

In [11]: %timeit is_odd(123443112344312)
10000000 loops, best of 3: 164 ns per loop

versus

def is_odd2(num):
   return num % 2 != 0

In [10]: %timeit is_odd2(123443112344312)
1000000 loops, best of 3: 267 ns per loop

或者，使返回值与is_odd:

def is_odd3(num):
   return num % 2

In [21]: %timeit is_odd3(123443112344312)
1000000 loops, best of 3: 205 ns per loop