Python TypeError: list indices must be integers or slices, not tuple Solution

A list is a data structure in Python that stores elements of different data types sequentially. We can access each element using its index number. The list provides a unique sequential integer value to every element called the index number, which starts from 0 and ends at n-1 (n is the total number of elements present in the list).

When we wish to access any list elements, we use its index number inside the square bracket preceded by the list name. But, if we specify a tuple object instead of an index value to access a list element, we receive the TypeError: list indices must be integers or slices, not tuple Error.

In this tutorial, we will learn what TypeError: list indices must be integers or slices, not tuple error is and how to solve it. We will also look at a common scenario example and a corresponding solution example.

Python Error: TypeError: list indices must be integers, not tuple

The Python error TypeError: list indices must be integers, not tuple is divided into two statements Error Type and Error Message.

1. Error Type ( TypeError ): TypeError occurs in Python when we incorrectly operate a Python object type.
2. Error Message ( list indices must be integers or slices, not tuple ): This error message tells us that we are using a tuple object instead of a valid index value.

Error Reason

The reason for this error is quite obvious. If you look at the error message, you can tell why this error occurred in your program. Python list index value is always an integer value. Even in list slicing, we use index integer values separated with colons.

But if we pass a tuple or values separated by commas as an index value, we will receive the list indices must be integers or slices, not tuple Error.

Example

my_list =['a', 'b', 'c', 'd', 'e', 'f']

# access list first element
print(my_list[0,])

Output

Traceback (most recent call last):
File "main.py", line 4, in <module>
print(my_list[0,])
TypeError: list indices must be integers or slices, not tuple

Break the code

We receive the error in the above program because, at line 4, we passed a tuple as an index value to access the first element of my_list .

The Python interpreter read the comma-separated values as a tuple. That's why in line 4, where we printed the my_list first, the element using the index value 0, .

Python treated the 0, statement as a tuple and threw the error because the index value must be an integer, not a tuple.

Solution

To solve the above program, we just need to remove the comma after 0 , which will be treated as an integer object.

my_list =['a', 'b', 'c', 'd', 'e', 'f']

# access list first element
print(my_list[0])

Output

a

A Common Scenario

The most common scenario where many Python learners encounter this error is when they use commas , by mistake for list slicing instead of a colon : .

Example:

Let's say we want to access the first four elements from our list, and slicing would be a perfect choice for that list. We can access a sequential part of the list using a single statement using list slicing.

my_list =['a', 'b', 'c', 'd', 'e', 'f']

# access first 3 elements
print(my_list[0,4])

Output

Traceback (most recent call last):
File "main.py", line 4, in <module>
print(my_list[0,4])
TypeError: list indices must be integers or slices, not tuple

Break the code

In the above example, we tried to perform Python list slicing on our list object my_list to access its first three elements. But in line 4, instead of a colon : we used commas to specify the start 0 and end 4 indices for the list slicing.

Python interpreter read the 1,4 statement as a tuple and return the TypeError list indices must be integers or slices, not tuple .

Solution

The solution to the above problem is very simple. All we need to do is follow the correct Python list-slicing syntax that is as follows:

list_name[start_index : end_index : steps]

Example

my_list =['a', 'b', 'c', 'd', 'e', 'f']

# access first 3 elements
print(my_list[0:4])

Output

['a', 'b', 'c', 'd']

Final Thoughts!

In this Python tutorial, we learned about TypeError: list indices must be integers or slices, not tuple Error and how to solve it. This error arises in Python when we use a tuple object instead of the integer index value to access an element from a Python list.

To solve this problem, you need to make sure that the error list element you are using must be accessed through a proper index value, not a tuple.

If you are still getting this error in your Python program, you can share your code in the comment section with the query, and we will help you to debug it.

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