Python Program - Print all Prime Numbers in an Interval

Here's a Python program to print all prime numbers in an interval:

# function to check if a number is prime or not
def is_prime(n):
    # check if n is 2, the only even prime number
    if n == 2:
        return True
    # check if n is even or less than 2
    if n % 2 == 0 or n < 2:
        return False
    # check if n is divisible by any odd number less than n
    for i in range(3, int(n ** 0.5) + 1, 2):
        if n % i == 0:
            return False
    return True

# take input from user
lower = int(input("Enter lower limit of the interval: "))
upper = int(input("Enter upper limit of the interval: "))

# print all prime numbers in the interval
print(f"Prime numbers between {lower} and {upper} are:")
for num in range(lower, upper + 1):
    if is_prime(num):
        print(num)

In this program, we first define a function is_prime(n) that takes a number n as input and returns True if it is prime, and False otherwise. We use the fact that a number is prime if it is not divisible by any number except 1 and itself. We first check if n is 2, the only even prime number. If not, we check if n is even or less than 2, in which case it is not prime. Otherwise, we check if n is divisible by any odd number less than n using a loop that starts from 3 and goes up to the square root of n, checking only odd numbers.

Then, we take input from the user for the lower and upper limits of the interval, and use a loop to iterate over all numbers in the interval. For each number, we call the is_prime() function to check if it is prime, and print it if it is.