Write a python program to check whether the given number is prime or not. Let’s create some examples in python to validate a prime number, also, will find the total count of prime numbers from an array.

A number that is divisible by 1 or itself is a called prime number like **7, 17, 19, 23,** etc. **A prime number can not be a negative number(-2,-5, etc..)**

## Check whether the number is prime or not in Python

**Step 1** Create a function with a parameter

**Step 2 C**hecking whether the number is negative or positive

**Step 3 **If it is positive then we run a loop from 2 to the range of number and then check if the range number and the given number are divisible by it and give zero as a reminder if it is so then the number is not prime

**Step 4 **But if it is not divisible then the number is a prime number

**Step 5 **As we are using the function we will use the return method to give the output

**Input and Output Sample**

Input = 17

Output = it’s a prime number

Input = 16

Output = it’s a not prime number

### Algorithm to find Prime number in Python

- Creating a function with a parameter to take input
- Check whether the entered parameter(input) is negative or positive
- We will check whether the number is prime or not by running a loop with itself and dividing it and checking the remainder
- If the remainder is zero it is not a prime number
- If the remainder is not zero it is a prime number

#### Python Code to check whether the number is prime or not

def is_prime_number(num): if num > 1: for i in range(2, int(num/2)+1): if (num % i) == 0: return "is not a prime number" else: return "is a prime number" else: return "is not a prime number" num=17 print(num,is_prime_number(num)) num2=16 print(num2,is_prime_number(num2))

#### Output

**In this article part, we have seen how to check whether the number is a prime number or not, if we want the value as true or false we just replace the return part with true and false as per the condition.**

## Write a python program to find the count of prime numbers in an array

**Step 1** we import our previous file using the import keyword and give it an alias name for convenience

**Step 2 **Then creates a function that takes an array as a parameter

**Step 3** Then set the counter at zero

**Step 4 **Using for loop and accessing a single element at a time to check whether the number is prime or not

**Step 5** By the **is_prime_number ** method of the previous code, we give a single element and check whether the condition is satisfied or not

**Step 6** If satisfied then the count stays the same while if not then the count will update once

**Step 7** As we are using the function we return the result using the return keyword

**Step 8** At the end, we create an instance to check our code

### Algorithm to count prime numbers in an array

- Importing the previous code of checking the prime number validation
- Creating a function with a parameter that will take an array
- Set a counter to zero to start counting the prime number
- Now we run the array in the loop for accessing each element
- Check whether the accessed element is negative or positive
- Then giving value to the function of the previous code, we will check whether the number is prime or not
- Update count every time if it is a prime number

## Python code to count prime numbers in an array

import prime_number as pn def total_prime_number(arr): count=0 for i in arr: if pn.is_prime_number(i) == "is not a prime number": count=count else: count=count+1 return count arr=[24,31,27,23,54,45]x print(total_prime_number(arr))

#### Output

**In this article, we have learned how to check any prime number and in another part, we have also seen how to count all the prime numbers in a given array**