check a number is prime number or not in python code example
Example 1: 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 2: prime checker in python
#make the function
#to do this all hte vairibles go in side the function
def CheckIfPrime ():
a1 = input("which number do you want to check")
a = int(a1)#you need the checking number as an int not an str
b = 2 #the number to check againts
c = ("yes")
while b < a:#run the loop
if a%b == 0:#check if the division has a remainder
c = ("no")#set the answer
b = b+1
print(c)#print the output
CheckIfPrime ()#call the function