The abacus module is an example of module metaprogramming in service of developer experience.

The end-user APIs for plain_abacus and abacus are the same. Please view their module-level docstrings for examples.

But abacus uses metaprogramming to elliminate the code duplication in the add and sub functions of plain_abacus.

The metaprogramming features are:

• @command: decorator to register a method name as a command;
• @command_alias: decorator to register a method name and aliases as a command;
• _make_command: builds a stand-alone function from an Abacus method;
• _install_commands: makes commands and installs them as global functions;

Note: abacus has more lines of code and is much harder to understand than plain_abacus. However, this example was inspired by the jupyturtle project, where the Turtle class has many more methods than Abacus, therefore coding each global function by hand would require a lot of duplication and many more lines of code.

When using metaprogramming, it's always a good idea to consider whether the added complexity is worthwhile.