Python program to print even numbers in a list

Python lists are fundamental data structures that store collections of items. Finding even numbers in a list is a common programming task with multiple efficient approaches. A number is even if it divides by 2 with no remainder.

We will explore several methods to print even numbers from a list, each with different advantages ?

Using Modulo Operator

The modulo operator (%) returns the remainder when dividing two numbers. For even numbers, x % 2 == 0 will be true.

Example

def print_evens(numbers):
    for num in numbers:
        if num % 2 == 0:
            print(num, end=' ')

print_evens([5, 20, 21, 58, 3])

20 58 

Using Bitwise AND Operator

In binary representation, even numbers have their least significant bit (rightmost) as 0. Using num & 1 == 0 checks if the last bit is unset ?

Example

def print_evens_bitwise(numbers):
    for num in numbers:
        if num & 1 == 0:
            print(num, end=' ')

print_evens_bitwise([5, 20, 21, 58, 3])

20 58 

Checking Last Digit

Even numbers always end with 0, 2, 4, 6, or 8. We can check if num % 10 is in this set ?

Example

def print_evens_last_digit(numbers):
    for num in numbers:
        if num % 10 in (0, 2, 4, 6, 8):
            print(num, end=' ')

print_evens_last_digit([5, 20, 21, 58, 3])

20 58 

Using filter() Function

Python's built-in filter() function creates an iterator of elements that satisfy a condition ?

Example

def print_evens_filter(numbers):
    even_numbers = filter(lambda x: x % 2 == 0, numbers)
    for num in even_numbers:
        print(num, end=' ')

print_evens_filter([5, 20, 21, 58, 3])

20 58 

One-liner with filter()

Using the unpacking operator (*) with filter() provides the most concise solution ?

Example

def print_evens_oneliner(numbers):
    print(*filter(lambda x: x % 2 == 0, numbers))

print_evens_oneliner([5, 20, 21, 58, 3])

20 58

Comparison

Conclusion

The modulo operator method is most commonly used due to its clarity. The bitwise approach offers the best performance, while filter() provides elegant functional programming solutions.