How To Check If An Integer Is Odd (Or Even) With Python

Just for fun, how many ways can we determine if an integer, just an integer, (not a float) is odd or even?

Is Odd

Rules: Must return True if odd and False if even.

def is_odd_1(x):
    return x % 2 != 0

def is_odd_2(x):
    return ((-1)\*\*x) != 1

def is_odd_3(x):
    return x - 2 \* (x // 2) == 1

def is_odd_4(x):
    return (x & 1) == 1

def is_odd_5(x):
    return x / 2 != x // 2

Is Odd Or Even

Rules: Must return odd if odd and even if even.

def is_odd_even_1(x):
    return 'odd' if x % 2 else 'even'

def is_odd_even_2(x):
    return 'odd' if x & 1 else 'even'

def is_odd_even_3(x):
    return x % 2 and 'odd' or 'even'

Check All Functions

def check():
    nums = [10, 11]
    is_odds = [is_odd_1, is_odd_2, is_odd_3, is_odd_4, is_odd_5, is_odd_5]
    is_odd_evens = [is_odd_even_1, is_odd_even_2, is_odd_even_3]

    for i, num in enumerate(nums):
        if i == 0:
            print('\nExpected: False')
        else:
            print('\nExpected: True')

        for is_odd in is_odds:
            r = is_odd(num)
            print(is_odd.__name__, r)

        if i == 1:
            print('\nExpected: even')
        else:
            print('\nExpected: odd')

        for is_odd_even in is_odd_evens:
            r = is_odd_even(num)
            print(is_odd_even.__name__, r)

Thanks for reading. x

Resources

• Python: https://python.org