How Can I Find All Indices of a Specific Element in a Python List?

Obtaining All Occurrences of an Element in a List

While Python's index() method provides the index of an element's first occurrence, this article explores an efficient trick to retrieve all its occurrences in a list.

The Solution: List Comprehension with Enumeration

To accomplish this, we employ a list comprehension along with the enumerate() function:

indices = [i for i, x in enumerate(my_list) if x == "whatever"]

Understanding the Implementation

The enumerate(my_list) function generates pairs of the form (index, item) for every item in the list. Subsequently, the list comprehension retrieves the index i and the list item x from these pairs.

By applying the condition x == "whatever", we filter the pairs to only include those where x matches our desired value. The resulting list indices contains the indices of all occurrences of "whatever" in the original list.

This technique is especially useful when you need to perform subsequent operations on multiple occurrences of a particular element within a list, without iterating over it.

The above is the detailed content of How Can I Find All Indices of a Specific Element in a Python List?. For more information, please follow other related articles on the PHP Chinese website!