### TypeError: list indices must be integers or slices not tuple

###### In case you declared a tuple by mistake, tuples are constructed in multiple ways: Using a pair of parentheses creates an empty tuple; Using a trailing comma - a, or (a,) Separating items with commas - a, b or (a, b) Using the tuple() constructor; If you use numpy and are trying to access a nested list with two indices, make sure to convert the list to a numpy array first.