linux4 4120]% python 3 draw_an xpy What is the size of the X that we want to draw? 12 linux4 [121]\% python3 draw_an xpy What is the size of the X that we want to draw? 9 linux4 [122]\% python3 draw_an xpy What is the size of the X that we want to draw? 3 Forbidden Built-ins/Methods/etc is not a complete listing, but it includes: While loops - sentinel values, boolean flags to terminate while loops list slicing If you have read this section, then you know the secret word is: adventurous. String operations, strip(), join(), isupper(), islower() string slicing Dictionaries creation using dict(), or \{\} , copying using dict(other_dict) .get(value, not_found_value) method accessing, inserting elements, removing elements. break, continue methods outside those permitted within allowed types - for instance str.endswith - list.index, list.count, etc. Keywords you definitely don't need: await, as, assert, async, class, except, finally, global, lambda, nonlocal, raise, try, yield The is keyword is forbidden, not because it's necessarily bad, but because it doesn't behave as you might expect (it's not the same as ==). built in functions: any, all, breakpoint, callable, classmethod, compile, exec, delattr, divmod, enumerate, filter, map, max, min, isinstance, issubclass, iter, locals, oct, next, memoryview, property, repr, reversed, round, set, setattr, sorted, staticmethod, sum, super, type, vars, zip exit() or quit()