purePython

purePython is a designation used in the Python ecosystem to describe code, packages, or modules that are implemented entirely in Python without relying on compiled extensions written in C or other languages. Such code is typically portable across platforms and interpreters, since it does not require platform-specific builds or a C compiler for installation. In packaging, purePython components are often distributed with a wheel tag like py3-none-any to indicate platform independence.

purePython packages emphasize compatibility and ease of installation. They can be installed in environments where a compiler is unavailable and are usually compatible with a wide range of Python versions. They tend to rely on the Python standard library or other purePython modules, which can affect performance but improves portability and auditability.

Limitations of purePython include potential slower execution compared with optimized C extensions or specialized libraries. Some workloads benefit from native code or vectorized operations, and some libraries offer both purePython and native paths, leaving the choice to users or installers based on environment constraints.

Usage considerations include distribution strategy and testing. When broad compatibility is a goal, maintaining a purePython path can simplify installation across diverse systems and packaging tools. Developers may also provide optional C extensions that users can install when a build environment is available.

See also: CPython, PyPI, wheel, C extension, Python packaging, interoperability.