Python Indexing a sublist

In this tutorial, we are going to write a program that finds the index of a sublist element from the list. Let's see an example to understand it clearly.

Input

nested_list = [[1, 2, 3], [4, 5], [6, 7, 8, 9]]

Output

Index of 7:- 2 Index of 5:- 1 Index of 3:- 0

Let's see the simple and most common way to solve the given problem. Follow the given steps solve it.

• Initialize the list.
• Iterate over the list using the index.
• Iterate over the sub list and check the element that you want to find the index.
• If we find the element then print and break it

Example

 Live Demo

# initializing the lit nested_list = [[1, 2, 3], [4, 5], [6, 7, 8, 9]] # function to find the index def index(element): # initializing a flag for tracking the element is_found = False # iterating over the list for i in range(len(nested_list)):    # iterating over the sub list    for j in range(len(nested_list[i])):       # cheking for the element       if nested_list[i][j] == element:          # printing the sub list index that contains the element          print(f'Index of {element}: {i}')          # changing the flag to True          is_found = True       # breaking the inner loop       break    # breaking the outer loop    if is_found:       break    # checking whether the element is found or not    if not is_found:       # printing the element not found message       print("Element is not present in the list") index(7) index(5) index(3)

Output

If you run the above code, then you will get the following result.

Index of 7: 2 Index of 5: 1 Index of 3: 0

Conclusion

If you have any queries regarding the tutorial, mention them in the comment section