Python Program To Check Prime Number Using Function
Chapter:
Python
Last Updated:
27-04-2023 16:44:27 UTC
Program:
/* ............... START ............... */
def is_prime(n):
"""
Returns True if n is a prime number, False otherwise.
"""
if n < 2: # 0 and 1 are not primes
return False
for i in range(2, int(n**0.5) + 1):
if n % i == 0:
return False
return True
# example usage
num = 17
if is_prime(num):
print(num, "is a prime number")
else:
print(num, "is not a prime number")
/* ............... END ............... */
Output
17 is a prime number
If you change the value of num to a non-prime number, like 20, then the program will output "20 is not
a prime number".
Notes:
-
This program checks whether a given number is a prime number or not.The program defines a function called is_prime, which takes an integer n as input. The function checks whether n is less than 2, because any number less than 2 cannot be a prime number. If n is less than 2, the function returns False indicating that it is not a prime number.
- If n is greater than or equal to 2, then the function proceeds to check if n is divisible by any number from 2 to the square root of n. If n is divisible by any number between 2 and the square root of n, then n is not a prime number, and the function returns False.
- If the loop completes without finding any factors, then the number n is a prime number, and the function returns True.
- Finally, the program uses the is_prime function to check whether a number is prime or not, and prints the appropriate message.
Tags
Python Program To Check Prime Number Using Function #Python find prime numbers in range #Prime number in Python