If a function isn't showing any output, it might be because: Your function doesn't have a return statement You did not call show() on the output of a plotting function. Your code may have an error before the lines producing output Automatic printing doesn't happen for statements inside functions or for loops You need to use (call) the function, not just define it Fill in the blanks: A function is a selection of for the computer to follow. The code that is indented is the function . Unindenting marks the end of the function. Thinking about what to make a function's input is a similar process to writing a What's different, and what stays the same