Python | Count occurrences of an element in a list

Python | Count occurrences of an element in a list

In this tutorial, we'll explore how to count the occurrences of a particular element in a list in Python.

Objective:

Given a list lst and an element ele, count the number of times ele appears in lst.

For Example: Given the list and element:

lst = [1, 2, 3, 2, 1, 5, 6, 3, 2] ele = 2

The element 2 appears 3 times in the list.

Step-by-step Solution:

1. Using the count method:

Python's list provides a built-in method count, which returns the number of times a particular element appears in the list.

Code:
lst = [1, 2, 3, 2, 1, 5, 6, 3, 2] ele = 2 occurrences = lst.count(ele) print(f"The element {ele} appears {occurrences} times in the list.")

2. Using a loop:

While the count method is the most efficient for this task, one can also achieve the result using a loop to manually count occurrences.

Code:
lst = [1, 2, 3, 2, 1, 5, 6, 3, 2] ele = 2 occurrences = 0 for item in lst: if item == ele: occurrences += 1 print(f"The element {ele} appears {occurrences} times in the list.")

3. Using List Comprehension:

Another alternative is to use list comprehension along with the len function to determine the number of occurrences.

Code:
lst = [1, 2, 3, 2, 1, 5, 6, 3, 2] ele = 2 occurrences = len([item for item in lst if item == ele]) print(f"The element {ele} appears {occurrences} times in the list.")

Recommendations:

For most use cases, the built-in count method is recommended due to its simplicity and efficiency. However, if you're working on a problem where you need to manually inspect each element during iteration, using a loop might be more appropriate.

Through this tutorial, you've learned multiple ways to count the occurrences of a specific element in a list in Python.

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