SyntaxWarning: list indices must be integers or slices, not tuple; perhaps you missed a comma?

This warning occurs when trying to use a tuple as an index for a list. In Python, list indices must be integers or slices, not tuples.

For example, if we have a list of lists and we want to access an element in a specific sublist using a tuple as an index, we will get this warning:

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

# Trying to access an element in a specific sublist using a tuple as an index
sublist_index = (1, 2)
element = list_of_lists[sublist_index]  # Raises a SyntaxWarning

To fix this warning, we need to use a comma to separate the tuple elements and convert it to an integer index:

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

# Accessing an element in a specific sublist using an integer index
sublist_index = 1
element = list_of_lists[sublist_index][2]  # Returns 6