number while number < four spacesindentation indicate "blockof code print(numbernumber + print('done!'the block forms the repeated lines the first unindented line marks the end of the block the four spaces of indentation are not cosmetic sequence of lines that have the same indentation form blocks in python and can be thought of as single unit of code in this case both lines get run (againor neither of them do the indented block is ended by the first line that follows it with no indentation