Python | Test if string contains element from list

We are given a String and our task is to test if the string contains elements from the list.

Example:

Input:    String: Geeks for Geeks is one of the best company.
        List: ['Geeks', 'for']

Output:    Does string contain any list element : True

Naive Approach checking each word in the string

Here we are splitting the string into list of words and then matching each word of this list with the already present list of words we want to check.

The original string : There are 2 apples for 4 persons
The original list : ['apples', 'oranges']
String contains the list element

Using list comprehension to check if string contains element from list

This problem can be solved using the list comprehension, in this, we check for the list and also with string elements if we can find a match, and return true, if we find one and false is not using the conditional statements.
 

The original string : There are 2 apples for 4 persons
The original list : ['apples', 'oranges']
Does string contain any list element : True

Using any() to check if string contains element from list

Using any function is the most classical way in which you can perform this task and also efficiently. This function checks for match in string with match of each element of list.
 

The original string : There are 2 apples for 4 persons
The original list : ['apples', 'oranges']
Does string contain any list element : True

Using find() method to check if string contains element from list

Here we are using the find() method to check the occurrence of the word and it returns -1 if the word does not exist in the list.

The original string : There are 2 apples for 4 persons
The original list : ['apples', 'oranges']
Does string contain any list element : True

Using Counter() function

The original string : There are 2 apples for 4 persons
The original list : ['apples', 'oranges']
Does string contain any list element : True

Time Complexity: O(N)

Auxiliary Space: O(N)

Using Set Intersection to Check if String Contains Element from List

One approach to check if a string contains an element from a list is to convert the string and the list into sets and then check for the intersection between the sets. If the intersection is not an empty set, it means that the string contains an element from the list.

The original string: There are 2 apples for 4 persons
The original list: ['apples', 'oranges']
String contains an element from the list

This approach has a time complexity of O(n) and an auxiliary space of O(n).

Using operator.countOf() method.

The original string : There are 2 apples for 4 persons
The original list : ['apples', 'oranges']
Does string contain any list element : True

Time Complexity: O(n)

Auxiliary Space: O(1)

Using operator.contains() method

Approach

1. Initiate a for loop to traverse list of strings and set res to False
2. Check whether each string of list is present in given string
3. If yes set res to True and break out of for loop
4. Display res

The original string : There are 2 apples for 4 persons
The original list : ['apples', 'oranges']
Does string contain any list element : True

Time Complexity : O(M*N) M-length of test_list N-length of test_string

Auxiliary Space : O(1)

Approach#9:using lambda

Algorithm

1. Take the input string and a list of words from the user.
2. Define a lambda function contains_word() using lambda, map() and any() functions to check if any element from the list is present in the string.
3. Call the contains_word() function with the input string and the list of words as arguments.
4. Print the result.

String contains at least one word from list.

Time complexity: O(n*m) where n is the length of the input string and m is the length of the list of words. This is because we are using the in operator to check if each element of the list is present in the string, which takes linear time.

Space complexity: O(n) where n is the length of the input string. This is because we are storing the input string in memory. The space used by the list of words and the lambda functions is negligible compared to the input string.