Easily Find the Index of a List Element in Python

In this tutorial, you will learn how to find the position or index of a list element in Python.

Python List index() method

With help of the index() method, you can find the position or index number of an element of a Python list.

Syntax of the index() method

This method can take up to three parameters or arguments (the last two parameters are optional).

list.index(element, start, end)

1. element – the element you want to search.
2. start (optional) – Index number from where you want to start the searching.
3. end (optional) – search the element up to this index number.

This method returns the index number of the given element. But if the given element is not found, a ValueError exception will appear.

>>> a = [32, 16, 28, 'Python', 54.8]
>>> indexNum = a.index('Python')
>>> print(indexNum)
3
>>>

>>> a = [32, 16, 28, 'Python', 54.8]
>>> indexNum = a.index(54)
ValueError: 54 is not in list
>>>

Example with Start and End Parameters

>>> a = [32, 16, 28, 'Python', 54.8]
>>> indexNum = a.index(28, 1, 4)
>>> print(indexNum)
2
>>>