TASK DEFINITION: In this task, you will be given a list.  The list is several integers and letters separated with a comma, written within a []. You can create new lists by dropping one of the items in the input list. Your task is to write a list containing all the possible lists you can make by dropping one item from the input list. For example, if the input list contains two items, you can drop one of the items each time. So the output should be a list comprising two inner lists that you have created by decreasing the items.
PROBLEM: ['X', 'x', 'a', 'b', 'p', 'U', '7']

SOLUTION: [['X', 'x', 'a', 'b', 'p', 'U'], ['X', 'x', 'a', 'b', 'p', '7'], ['X', 'x', 'a', 'b', 'U', '7'], ['X', 'x', 'a', 'p', 'U', '7'], ['X', 'x', 'b', 'p', 'U', '7'], ['X', 'a', 'b', 'p', 'U', '7'], ['x', 'a', 'b', 'p', 'U', '7']]

PROBLEM: ['9', '7', '3', 'Z', '9']

SOLUTION: [['9', '7', '3', 'Z'], ['9', '7', '3', '9'], ['9', '7', 'Z', '9'], ['9', '3', 'Z', '9'], ['7', '3', 'Z', '9']]

PROBLEM: ['6', '6', '4']

SOLUTION:
[['6', '6'], ['6', '4'], ['6', '4']]