Python program to filter prime numbers

Last update on April 22 2025 12:54:17 (UTC/GMT +8 hours)

7. Prime Number Excluder

Write a Python program that filters out prime numbers from a list of integers using the filter function.

Sample Solution:

Python Code:

# Define a function to check if a number is prime
def is_prime(n):
    if n <= 1:
        return False
    if n <= 3:
        return True
    if n % 2 == 0 or n % 3 == 0:
        return False
    i = 5
    while i * i <= n:
        if n % i == 0 or n % (i + 2) == 0:
            return False
        i += 6
    return True

# Define a list of integers
numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17]
print("List of integers:")
print(numbers)

# Use the filter function to extract prime numbers
prime_numbers = list(filter(is_prime, numbers))
print("\nExtract prime numbers of the said list:")
# Print the extracted prime numbers
print(prime_numbers)

Explanation:

In the exercise above,

First, we define a function called "is_prime()" that checks if a given number n is prime. This function uses the primality test with optimizations.
Define a list called 'numbers' containing integers.
Next, we use the filter function to filter out prime numbers from the numbers list by applying the "is_prime()" function as the filtering condition.
The filtered prime numbers are converted to a list, and we print the extracted prime numbers.

Sample Output:

List of integers:
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17]

Extract prime numbers of the said list:
[2, 3, 5, 7, 11, 13, 17]

Flowchart:

For more Practice: Solve these Related Problems:

Write a Python program to filter out prime numbers from a list and return a list containing only composite numbers using the filter function.
Write a Python function that separates prime and non-prime numbers from a list using filter, returning a tuple of two lists.
Write a Python program to use the filter function to remove prime numbers from a list, then compute the sum of the remaining composite numbers.
Write a Python program that filters out numbers that are prime (excluding 0 and 1) from a list using the filter function.

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