Ответ: как проверить чётность числа в Python?

Question

me@amadeus:~$ python3 -q
>>> def check(n):
...     if not isinstance(n, int):
...         print(f&#34;The value {n} is not an integer value&#34;)
...         return None
...     if not n: return (n, &#34;undefined&#34;)
...     if n & 1: return (n, &#34;odd&#34;)
...     return (n, &#34;even&#34;)
... 
>>> check(0)
(0, &#34;undefined&#34;)
>>> check(10)
(10, &#34;even&#34;)
>>> check(-10)
(-10, &#34;even&#34;)
>>> check(11)
(11, &#34;odd&#34;)
>>> check(-11)
(-11, &#34;odd&#34;)
>>> check(10.5)
The value 10.5 is not an integer value
>>> check(-11.5)
The value -11.5 is not an integer value
>>> check(-0)
(0, &#34;undefined&#34;)
>>> 
me@amadeus:~$ 
me@amadeus:~$ python3 -q
>>> def check(n):
...     match n:
...         case _ if not isinstance(n, int):
...             print(f&#34;The value {n} is not an integer value&#34;)
...             return None
...         case 0:
...             return (n, &#34;undefined&#34;)
...         case _ if n & 1:
...             return (n, &#34;odd&#34;)
...         case _:
...             return (n, &#34;even&#34;)
... 
>>> check(0)
(0, &#34;undefined&#34;)
>>> check(10)
(10, &#34;even&#34;)
>>> check(-10)
(-10, &#34;even&#34;)
>>> check(11)
(11, &#34;odd&#34;)
>>> check(-11)
(-11, &#34;odd&#34;)
>>> check(10.5)
The value 10.5 is not an integer value
>>> check(-11.5)
The value -11.5 is not an integer value
>>> check(-0)
(0, &#34;undefined&#34;)
>>> 
me@amadeus:~$

def check(n):
    if not isinstance(n, int):
        print(f&#34;The value {n} is not an integer value&#34;)
        return None
    if not n: return (n, &#34;undefined&#34;)
    if n & 1: return (n, &#34;odd&#34;)
    return (n, &#34;even&#34;)

def check_(n):
    match n:
        case _ if not isinstance(n, int):
            print(f&#34;The value {n} is not an integer value&#34;)
            return None
        case 0:
            return (n, &#34;undefined&#34;)
        case _ if n & 1:  
            return (n, &#34;odd&#34;)
        case _:  
            return (n, &#34;even&#34;)
Alex Gaudino feat. Crystal Waters - Destination Calabria [Explicit Version] [Official Video] - YouTube: 
https://www.youtube.com/watch?v=Kq4OtRsdXls

iurii_semykin · Accepted Answer

def tst(n):
    try:
        return ('чётное','нечётное')[n&1]
    except:
        return 'tst: параметр не целое!'
a=(1,3,2,0,'s',7)
for i in a:
    print( i,'  ',tst(i) )

eduard_osipov_24 · Answer

четность можно проверить делением пополам, на целое и не целое