List Index – Find the Index of an element in a List in Python

List Index –

The index method of list returns the index of the specified element in the list.

Syntax of List Index –

list.index(element, start, end)

element – The index of the element that you want to find.

start – start index from where you want to start the search

end – end index up to where you want to search

Find the Index of an Element in a List –

In [1]: companies = ['Google','Microsoft','Facebook','Apple','Google','Netflix']

In [2]: # find the index of google

In [3]: companies.index('Google')
Out[3]: 0

In [4]: # find the index of Apple

In [5]: companies.index('Apple')
Out[5]: 3

Find the Index when Element Not Present –

In [6]: # find index when element not in list

In [7]: companies.index('Amazon')
Traceback (most recent call last):

  File "C:\Users\BHOLA\AppData\Local\Temp\ipykernel_23336\3325088722.py", line 1, in <module>
    companies.index('Amazon')

ValueError: 'Amazon' is not in list

Example of Start and End Index –

In [8]: # find index of google after 1st index

In [9]: companies.index('Google',1)
Out[9]: 4

In [10]: # find the index of Google between 1st and 3rd index 

In [11]: companies.index('Google',1,3)
Traceback (most recent call last):

  File "C:\Users\BHOLA\AppData\Local\Temp\ipykernel_23336\2705779832.py", line 1, in <module>
    companies.index('Google',1,3)

ValueError: 'Google' is not in list