# Python – List Words Frequency in String

• Last Updated : 26 Mar, 2023

Given a List of Words, Map frequency of each to occurrence in String.

Input : test_str = ‘geeksforgeeks is best for geeks and best for CS’, count_list = [‘best’, ‘geeksforgeeks’, ‘computer’]
Output : [2, 1, 0]
Explanation : best has 2 occ., geeksforgeeks 1 and computer is not present in string.
Input : test_str = ‘geeksforgeeks is best for geeks and best for CS’, count_list = [‘better’, ‘gfg’, ‘computer’]
Output : [0, 0, 0]
Explanation : No word from list present in string.

Method #1 : Using defaultdict() + loop + list comprehension

In this, we compute words frequency using loop + defaultdict() and then use list comprehension to get all the counts corresponding to list of words.

## Python3

 `# Python3 code to demonstrate working of``# Divide String into Equal K chunks``# Using list comprehension``from` `collections ``import` `defaultdict` `# initializing strings``test_str ``=` `'geeksforgeeks is best for geeks and best for CS'` `# printing original string``print``(``"The original string is : "` `+` `str``(test_str))` `# initializing count_list``count_list ``=` `[``'best'``, ``'geeksforgeeks'``, ``'computer'``, ``'better'``, ``'for'``, ``'and'``]` `# computing frequency``res ``=` `defaultdict(``int``)``for` `sub ``in` `test_str.split():``    ``res[sub] ``+``=` `1``    ` `# assigning to list words``res ``=` `[res[sub] ``for` `sub ``in` `count_list]` `# printing result``print``(``"The list words frequency : "` `+` `str``(res))`

Output

```The original string is : geeksforgeeks is best for geeks and best for CS
The list words frequency : [2, 1, 0, 0, 2, 1]```

Time Complexity: O(n)
Auxiliary Space: O(n), where n is length of list.

Method #2 : Using Counter() + list comprehension

In this, Counter() is used to perform task of computing frequency, post that, list comprehension is used to assign frequency to list words.

## Python3

 `# Python3 code to demonstrate working of``# Divide String into Equal K chunks``# Using list comprehension``from` `collections ``import` `Counter` `# initializing strings``test_str ``=` `'geeksforgeeks is best for geeks and best for CS'` `# printing original string``print``(``"The original string is : "` `+` `str``(test_str))` `# initializing count_list``count_list ``=` `[``'best'``, ``'geeksforgeeks'``, ``'computer'``, ``'better'``, ``'for'``, ``'and'``]` `# computing frequency using Counter()``res ``=` `Counter(test_str.split())``    ` `# assigning to list words``res ``=` `[res[sub] ``for` `sub ``in` `count_list]` `# printing result``print``(``"The list words frequency : "` `+` `str``(res))`

Output

```The original string is : geeksforgeeks is best for geeks and best for CS
The list words frequency : [2, 1, 0, 0, 2, 1]```

Time complexity: O(N) since using a loop

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