Check if any element of List is in another List in Python

This tutorial will discuss about a unique way to check if any element of list is in another list in Python.

Suppose we have two lists,

strList1 = ['Sample', 'Like', 'This']
strList2 = ['That', 'Where', 'Why', 'This', 'Now']

Now we want to check if any element from first list i.e. strList1 exists in the second list i.e. strList2 or not.

For this, we can iterate over all the elements of first list, and during iteration, for each element check if it exists in the second list or not. If yes, then break the loop, and mark that an element from first list exists in the second list. We have created a function for this,

def is_overlapped(firstList, secondList):
    ''' Returns True, if any element from first list
        exists in the second List.'''
    result = False
    for item in firstList:
        if item in secondList:
            result = True
    return result

It accepts two lists as arguments, and retruns True, if any element from first list exists in the second List. Inside the function we will loop over all the elements of first list and check for their existence in the second list.

Let’s see some examples,

Example 1

In this example, the first list had an element that exists in the second list.

Let’s see the complete example,

def is_overlapped(firstList, secondList):
    ''' Returns True, if any element from first list
        exists in the second List.'''
    result = False
    for item in firstList:
        if item in secondList:
            result = True
    return result

# Example 1
strList1 = ['Sample', 'Like', 'This']
strList2 = ['That', 'Where', 'Why', 'This', 'Now']


if is_overlapped(strList1, strList2):
    print('Yes, an element of first List is in second List')
else:
    print('None of the element from first List is not in second List')

Output

Yes, an element of first List is in second List

Example 2

In this example, the first list and second list has no common elements.

Let’s see the complete example,

def is_overlapped(firstList, secondList):
    ''' Returns True, if any element from first list
        exists in the second List.'''
    result = False
    for item in firstList:
        if item in secondList:
            result = True
    return result

strList1 = ['Sample', 'Like', 'Text']
strList2 = ['That', 'Where', 'Why', 'This', 'Now']


if is_overlapped(strList1, strList2):
    print('Yes, an element of first List is in second List')
else:
    print('None of the element from first List is not in second List')

Output

None of the element from first List is not in second List

Summary

We learned how to check if any element of a List is present in another List in Python. Thanks.