7. Don’t repeat yourself (DRY)

It is easier to write '-' * 15 to produce 15 consecutive dashes than to type them out manually.

Small string-building idioms like this matter because they prevent hard-coded visual artifacts from scattering through the code. They also make the intent parameterizable if the width later needs to change.

7.1. Don’t do this

print('---------------')

7.2. Do this

print('-'*15)