Modular Programming with Python

Refactoring the code

We'll start our refactoring by moving the existing PNG renderers into a new sub-package called renderers.png. Create a new directory named png within the renderers directory, and move the title.py, x_axis.py, y_axis.py, bar_series.py and line_series.py modules into this directory. Then, create an empty package initialization file, __init__.py, inside the png directory so that Python will recognize it as a package.

There is one minor change we are going to have to make to our existing PNG renderers: because each renderer module imports the constants.py module using a relative import, we will need to update these modules so that they can still find the constants module from their new position. To do this, edit each PNG renderer ...