Python - List Words Frequency in String

Python – List Words Frequency in String

Last Updated : 30 Aug, 2020

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]

Method #2 : Using Counter() + list comprehension

In this, Counter() is used to perform task of computing frequency, post that, list comprehension is used to asign 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]

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