pytyped-macros 2.0.0

Type-Driven Development for Python: Shapes of Types

pytyped-macros

pytyped-macros is a core piece of pytyped Python packages that allows analysis of a given Python type and its breakdown into primitive type combinators. In this way, pytyped-macros facilitate pytyped's main goal of type-driven development in Python. pytyped-macros is designed to be an extensible base class upon which other type derivations are implemented. In order to see examples of how pytyped-macros can be used, look at pytyped-json, and pytyped-metrics.

Installation

You can install pytyped-macros from PyPI:

pip install pytyped-macros

pytyped-macros is checked on Python 3.6+.

Why pytyped-macros?

To our knowledge, pytyped-macros is the only Python package that supports type-based automation for all typing constructs including even recursive types that, up to this day, are not even fully supported by Python itself. Additionally, pytyped-macros is designed to be extensible. That is, you can create a sub-class of pytyped-macros's Extractor class to automate type derivation for your own task. To see examples of how this is done in practice, look at pytyped-json which uses pytyped-macros in order to automatically derive JSON decoders/encoders for a given Python type.

Currently, pytyped-macros supports the following type driven derivations:

• Derivations for basic types such as int, bool, date, datetime, str, and Decimal.
• Derivations for simple usual combinators such as List[T] and Dict[A, B].
• Derivations for named product types such as NamedTuples or dataclasses.
• Derivations for anonymous product types such as Tuple[T1, T2, ...].
• Derivations for anonymous union types such as Optional[T], Union[T1, T2, ...], etc.
• Derivations for named union types such as class hierarchies (i.e., when a class A has several subclasses A1, ..., An).
• Derivations for generic types and type variables.
• Derivations for custom functional types such as Set[T], Secret[T], etc where a custom function is defined for generic types such as Set or Secret and that functional is applied to all instantiations of those generic type.
• Derivations for recursive types such as binary trees, etc.

Defining New Type Automations

You can follow the examples of pytyped-json (for JSON decoders and JSON encoders), or pytyped-metrics for metric exporters to define new type-based automations. You just need to extend pytyped.macros.extractor.Extractor and implement the abstrtact methods there.

Issues

Please report any issues to the GitHub repository for this package.

Contributors

• Shahab Tasharrofi
• Ilyess Bachiri