Counter

The Counter class in Python, available in the collections module, is used to count the frequency of elements in a collection. It returns a dictionary-like object where the elements are keys and their counts are values.

To use the Counter class, you need to import it from the collections module:

from collections import Counter

Let's explore some practical examples of using the Counter class:

Example 1: Counting Elements in a List:

fruits = ["apple", "banana", "orange", "apple", "banana", "apple"]
fruit_counter = Counter(fruits)

print(fruit_counter)  # Output: Counter({'apple': 3, 'banana': 2, 'orange': 1})
print(fruit_counter["apple"])  # Output: 3
print(fruit_counter["banana"])  # Output: 2

In this code, we create a Counter object called fruit_counter from a list of fruits. The Counter object counts the frequency of each fruit. We can access the count of a specific fruit by indexing the fruit_counter object with the fruit name.

Example 2: Counting Characters in a String:

text = "Hello, world!"
char_counter = Counter(text)

print(char_counter)  # Output: Counter({'l': 3, 'o': 2, 'H': 1, 'e': 1, ',': 1, ' ': 1, 'w': 1, 'r': 1, 'd': 1, '!': 1})
print(char_counter["l"])  # Output: 3
print(char_counter["o"])  # Output: 2

In this code, we create a Counter object called char_counter from a string. The Counter object counts the frequency of each character in the string. We can access the count of a specific character by indexing the char_counter object with the character.