Jun 9, 2011 · This solution uses np.where and np.unique to find the indices of all unique elements in a list. Using np.where on an array (including the time to convert the list to an array) is slightly slower than a list-comprehension on a list, for finding all indices of all unique elements.

Dec 16, 2024 · In Python, counting the occurrences of all elements in a list is to determine how many times each unique element appears in the list. In this article, we will explore different methods to achieve this.

Dec 19, 2024 · Given a tuple and a list as input, write a Python program to count the occurrences of all items of the list in the tuple. Examples: Input : tuple = ('a', 'a', 'c', 'b', 'd') list = ['a', 'b'] Output : 3 Input : tuple = (1, 2, 3, 1, 4, 6, 7, 1, 4) list = [1, 4, 7] Output : 6 Approach #1 : Naive Appro

Sep 29, 2018 · Numpy is the best option. Still if you want, you can use simple if/else to flatten and return length of list. Example, flatten = [] for item in my_list: if isinstance(item, primitives): flatten.append(item) else: flatten.extend(item) return len(flatten)

Dec 3, 2024 · When working with lists in Python, we often need to extract specific elements. The easiest way to extract an element from a list is by using its index. Python uses zero-based indexing, meaning the first element is at index 0. Other methods that we can use to extract elements from list are:

The best answer here is to use all(), which is the builtin for this situation. We combine this with a generator expression to produce the result you want cleanly and efficiently. For example:

Jan 8, 2025 · In this guide, we’ll explore various methods for finding elements in Python find in list, along with practical examples and tips. Lists in Python are ordered, mutable, and can store a...

Mar 18, 2022 · How to Get Index of All Occurrences of Element in a Python List with a For Loop and Enumerate. One of the most basic ways to get the index positions of all occurrences of an element in a Python list is by using a for loop and the Python enumerate function. The enumerate function is used to iterate over an object and returns both the index and ...

Jun 10, 2023 · This concise, straightforward article will walk you through a few different ways to find all occurrences of a certain value in a list in Python. The desired result will be a list of indices of found elements.

Feb 2, 2021 · In this tutorial, we will introduce how to find the indices of all the occurrences of a specific element in a list. We will work with the following list and find all the indices of the element 1. We can easily iterate over the list and compare each element to the required element and find its indices. We can store the final result in a new list.