Python – Words Frequency in String Shorthands

Last Updated : 10 Jan, 2025

Word frequency in String Shirthands in Python typically refers to calculating how often words appear in a given string using various concise and efficient methods.

Using `collections.Counter`

Using collections.Counter allows you to count the frequency of each character in a string. By leveraging this, we can identify vowels and replace them with a specific character, like ‘K’, based on their frequency or presence in the string.

from collections import Counter

# Input string
s = "hello world hello everyone"

# Calculate word frequencies using Counter
w_freq = Counter(s.split())

print(w_freq)

Output

Counter({'hello': 2, 'world': 1, 'everyone': 1})

Explanation

Counter is used to count the frequency of each word in the string s by splitting the string into individual words using split().
output, {'hello': 2, 'world': 1, 'everyone': 1}, shows that the word “hello” appears twice, while “world” and “everyone” appear once each.

Using `dict.get()` with a `for` loop

Using dict.get() with a for loop allows you to efficiently count occurrences of each character or word in a string. The get() method retrieves the current count, and if the character or word isn’t in the dictionary yet, it returns a default value (usually 0).

# Input string
s = "hello world hello everyone"

# Initialize an empty dictionary to store word frequencies
w_freq = {}

# Calculate word frequencies using a for loop
for word in s.split():
    w_freq[word] = w_freq.get(word, 0) + 1

# Print the result
print(w_freq)

Output

{'hello': 2, 'world': 1, 'everyone': 1}

Explanation

for loop iterates over each word in the string s, splitting it into words. For each word, dict.get() is used to fetch the current frequency (or 0 if the word is not yet in the dictionary), and then the count is incremented.
The output is {'hello': 2, 'world': 1, 'everyone': 1}, which shows the frequency of each word in the string.

Using List Comprehension with `collections.Counter`

Using list comprehension with collections.Counter allows you to efficiently count the frequency of elements by transforming the data (such as characters or words in a string) and applying Counter to generate frequency counts.

from collections import Counter

# Input string
s = "hello world hello everyone"

# Calculate word frequencies using Counter and list comprehension
w_freq = Counter([word for word in s.split()])

# Print the result
print(w_freq)

Output

Counter({'hello': 2, 'world': 1, 'everyone': 1})

Explanation

This code uses a list comprehension to split the string into words and create a list of those words. The list is then passed to Counter, which calculates the frequency of each word.
The result, Counter({'hello': 2, 'world': 1, 'everyone': 1}), displays the word counts in the input string.

Using `map()` and `Counter`

Using map() with Counter combines functional programming and frequency counting. It applies a transformation to each element of an iterable using map() before passing the transformed iterable to Counter

from collections import Counter

# Input string
s = "hello world hello everyone"

# Calculate word frequencies using map and Counter
w_freq = Counter(map(str, s.split()))

print(w_freq)

Output

Counter({'hello': 2, 'world': 1, 'everyone': 1})

Explanation

Splits the string into words and applies str to ensure each item is treated as a string (though unnecessary here since split() already produces strings).
Counts the occurrences of each word and stores the result as a Counter object