FAQ

Why is it called conditional-method but I import cfg?

conditional-method is the PyPI distribution name; cfg is the import module — same convention as e.g. beautifulsoup4 → bs4.

Is there a pure-Python fallback?

No. The entire implementation is the C extension conditional_method._c; the package contains only a thin __init__.py shim. There is deliberately no pure Python implementation to maintain.

Why abi3?

abi3 (the Python Limited API / stable ABI) lets one wheel (cp39-abi3) run on every CPython 3.9+ release. Users on 3.14 get a wheel built for 3.9 without any rebuild, and maintainers publish far fewer artifacts.

What happens when two conditions are true?

The last true condition wins (source order). Only that implementation survives on the class.

What happens when no condition is true?

Class creation fails with TypeError: None of the conditions is true for ... (wrapped in RuntimeError by the interpreter on CPython < 3.13).

Can conditions be dynamic?

Yes — pass a callable condition; it is evaluated lazily each time the implementation is selected, so it can depend on runtime state.

Does it work with @property / @classmethod / @staticmethod?

Yes — see Usage. Note the decorator ordering:

@property
@cfg(condition=True)
def prop(self): ...

Is it fast?

The selection happens once at class build time; calling the selected method is a plain attribute lookup with zero overhead. See Benchmarks.

Does it have dependencies?

No runtime dependencies.

How do I debug it?

Set __conditional_method_debug__=true (any value except "false") to enable the C debug logger:

export __conditional_method_debug__=true