Find the k most frequent words from data set in Python

Given the data set, we can find k number of most frequent words.

The solution of this problem already present as Find the k most frequent words from a file. But we can solve this problem very efficiently in Python with the help of some high performance modules.

In order to do this, we’ll use a high performance data type module, which is collections. This module got some specialized container datatypes and we will use counter class from this module.


Examples :

Input : "John is the son of John second. 
         Second son of John second is William second."
Output : [('second', 4), ('John', 3), ('son', 2), ('is', 2)]

Explanation :
1. The string will converted into list like this :
    ['John', 'is', 'the', 'son', 'of', 'John', 
     'second', 'Second', 'son', 'of', 'John', 
     'second', 'is', 'William', 'second']
2. Now 'most_common(4)' will return four most 
   frequent words and its count in tuple. 


Input : "geeks for geeks is for geeks. By geeks
         and for the geeks."
Output : [('geeks', 5), ('for', 3)]

Explanation :
most_common(2) will return two most frequent words and their count.

Approach :

Import Counter class from collections module.
Split the string into list using split(), it will
return the lists of words. 
Now pass the list to the instance of Counter class
The function 'most-common()' inside Counter will return
the list of most frequent words from list and its count.

Below is Python implementation of above approach :

Output :

[('Geeks', 5), ('to', 4), ('and', 4), ('article', 3)]