Python is a popular programming language that offers a wide range of functionalities. One of these functionalities is the ability to find the index of an element in a list. We will explore the built-in functions to find the index of a list. This tutorial is designed for beginners who have some knowledge of Python programming and want to learn how to find the index of an element in a list.

Index of a list element :

  • Sometimes we need to get the index of a list element to use in our code.
  • We can get the index of an element of a list by using the  index()  method.
  • The syntax of using the index() method is as follows :

index = list_name.index(list_item)

  • The lists have zero based index i.e. the index of the first element is zero.
  • If we try to find index of an element that is not in the list then we get an error.
  • To avoid such situations, it is advised that we make use of  in operator before using the  index()  function.
  • the in operator can be used to check if an element is in the list or not.
  • Code Sample : 

def find_index(item):
    if item in my_list:
        index = my_list.index(item)
        print(f"Item {item} is at index {index}")
        print(f"Item {item} is not in my_list")

my_list = [1, 2, 3, 4]
# Output
# Item 3 is at index 2
# Item 5 is not in my_list

  • In the code above we have created a function named  find_index()  to find the index of the element of the list.
  • The element is passed as an argument to the function.
  • The function uses the  index()  function to find the index of the element.
  • If the element is not in the list the  find_index()  function prints a message.

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