Receipts should only show the last four digits of a payment card. Card numbers arrive with or without spaces between the groups of digits.
Write a function mask_card(number) that removes any spaces, then replaces every digit except the last four with *.
How it's checked
Your code runs, then the check below runs and its printed output is compared with ours.
mask_card("4111 2222 3333 4444") returns "************4444"def mask_card(number):
...