how to check prime number in 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: prime number in python

def prime(num):
    if num>1:
        s=int(num/2)
        for i in range(2,s+1):
            if num%i==0:
                return("not prime")
                break
        return("prime")
print(prime(239))

Example 4: 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 5: prime number program python

# Python program to display all the prime numbers within an interval

lower = 900
upper = 1000

print("Prime numbers between", lower, "and", upper, "are:")

for num in range(lower, upper + 1):
   # all prime numbers are greater than 1
   if num > 1:
       for i in range(2, num):
           if (num % i) == 0:
               break
       else:
           print(num)Copied

Example 6: 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