If any element which is not present is searched, then it returns the ValueError. The method index() returns the lowest index in the list that item appears.
Python List Index
Python list index() is an inbuilt function that searches an element in the list and returns its index. The list index() method returns the index of the element in the list.
Syntax
The syntax for the index() method is the following.
list.index(element)
Parameters
The element parameter is required, and it is the item that is searched for in the list.
Let us take an example.
# app.py
GoT = ['Daenerys', 'Jon', 'Tyrion']
elementIndex = GoT.index('Jon')
print(elementIndex)
So, the index() method returns an index, and in the above example, it returns Jon’s index which is 1.
Find Index of Item Which Doesn’t Exist
If we find an index of an element that is not present in the list, then it will return a ValueError. Let us see the following code.
# app.py
GoT = ['Daenerys', 'Jon', 'Tyrion']
elementIndex = GoT.index('Arya')
print(elementIndex)
See the output.
Find an index of tuple and list inside a list
Let us find an index of a tuple in the list. Let us look at the following example.
# app.py
GoT2 = ['Daenerys', 'Jon', ('Briane', 'Tormund') , 'Tyrion']
elementIndex2 = GoT2.index(('Briane', 'Tormund'))
print(elementIndex2)
See the output.
So, it works the same as a single element in the list because it behaves as a single element in a list.
Finally, Python List Index Example is over.
