prime number check python code example

Example 1: how to check if a number is prime in python

def prime(num):
        for x in range(2,num):
            if num % x == 0:
                return False
        return True

Example 2: determine if number is prime python

# Time Efficient Primality Check in Python

def primeCheck(n):
    # 0, 1, even numbers greater than 2 are NOT PRIME
    if n==1 or n==0 or (n % 2 == 0 and n > 2):
        return "Not prime"
    else:
        # Not prime if divisable by another number less
        # or equal to the square root of itself.
        # n**(1/2) returns square root of n
        for i in range(3, int(n**(1/2))+1, 2):
            if n%i == 0:
                return "Not prime"
        return "Prime"

Example 3: how to check if a number is prime in python

import math
def prime(x):
    if x == 2 or x == 3 or x==5:
        return True
    if x == 1 or x == 4:
        return False
    num = 2
    a= math.sqrt(x)+4 
    while a > num:
        if x % num == 0:
            return False
        else:
            num = num + 1
    return True