Most of the time, code should be written in such a way that it is easy to understand on its own. However, if you want to include a piece of information to explain a part of your code, you can use the
# sign. A line of text preceded by a
# is called a comment. The machine does not run this code — it is only for humans to read. When you look back at your code later, comments may help you figure out what it was intended to do.
# this variable counts how many rows of the spreadsheet we have: row_count = 13
Add a comment above the declaration of
city_pop with a description of what you think the variable contains.