If your program isn't given exactly one command line argument, it should print a usage message and exit immediately:

$[$dent@bistromath$]$$ python$3$ main.py USAGE: main.py menu.tsv

If the user tries to order something that isn't on the menu, your program should print an error message. It should not exit in this case; it should keep waiting for more user input.

$[$dent@bistromath$]$$ python$3$ main.py data$/$cheese$.$tsv TODAY'S MENU: Cheese $$50\mathrm{.}00$ What would you like to order? Cheese Wine Sorry, "Wine" isn't on the menu.

There might be whitespace $($spaces$,$ tabs$,$ newlines, etc.$)$ on either end of the user input. Use the strmember function strip$()$ to remove these spaces from each line of input before processing it$.$ If the result is an empty string, your program should ignore it and move on to the next line.

If the user hasn't successfully ordered anything by the time you reach the end of the user input, your program should exit without printing the order $($or the preceding newline$).$