nirs4all.utils.lazy module

Lazy module proxy for deferring heavy imports to first use.

Some modules (e.g. chart controllers) must be importable eagerly — the controller registry imports them at import nirs4all so routing knows about them — but only need a heavy dependency (matplotlib) when they actually render. Binding the dependency to a module-level LazyModule keeps the familiar plt = lazy_module("matplotlib.pyplot") name while deferring the real import until an attribute is first accessed, so importing the package stays cheap.

A module-level __getattr__ (PEP 562) cannot serve this purpose: it is only consulted for external attribute access on the package, not for internal global name lookups like plt.subplots(...) inside the module’s own functions. The proxy object is bound as a real global, so internal usage resolves normally and triggers the lazy import on the first attribute access.

class nirs4all.utils.lazy.LazyModule(name: str)

Bases: object

Proxy that imports the wrapped module on first attribute access.

The wrapped module is imported once and cached; every attribute access thereafter is a plain getattr on the real module.