Course Python style guide

Reference material. It belongs to no week, so it lives in Other course resources.

Names

• lower_snake_case for variables and functions.
• Names say what the value is, not what type it is: prices, not price_list.
• A single letter is fine for a loop index in a three-line loop and nowhere else.

Layout

• Four spaces per indent level. Never tabs.
• One blank line between functions; two at the top level of a file.
• Lines under 88 characters. If a line does not fit, the expression is usually doing too much.

Comments

Comment the decision, not the mechanism.

# Wrong: increments the counter
count += 1

# Right: an empty record still counts as a submission
count += 1

If a comment restates the code, delete one of them — and it is usually the comment.

Before you submit

1. Run the program on the supplied input and check the output matches.
2. Run it on an empty input and check it does something sensible.
3. Read your own diff. Anything you cannot explain does not go in.