check prime function in python code example

Example 1: 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

Example 2: python prime check

def isPrime(n):
  if n<2:		#1, 0 and all negative numbers are not prime
    return False
  elif n==2:	#2 is prime but cannot be calculated with the formula below becuase of the range function
    return True
  else:
    for i in range(2, n):
      if (n % i) == 0:	#if you can precisely divide a number by another number, it is not prime
        return False
    return True			#if the progam dont return False and arrives here, it means it has checked all the numebrs smaller than n and nono of them divides n. So n is prime