optional-dependency-hint 0.1.0

Print a hint when one of optional dependencies of a package not found

Optional Dependency Hint

This package gives a clearer ImportError message when an optional dependency is missing, including an install hint like pip install mypkg[extra].

Installation

pip install optional-dependency-hint

Requirements

• Python >=3.8

Quick Start

import optdep

# Declare `tqdm` as an optional dependency of `mypkg`
# and tell users how to install it.
optdep.add("tqdm", "mypkg", "progbar")

import tqdm
# If `tqdm` is missing:
# ImportError: Optional dependency tqdm is not installed.
# You may install it with mypkg by: `pip install mypkg[progbar]`

If you only want the default message without install instructions:

import optdep

optdep.add("tqdm")

import tqdm
# If `tqdm` is missing:
# ImportError: Optional dependency tqdm is not installed.

API

optdep.add(module_name, this_pkg_name=None, extra=None, exist_behavior="skip")

• module_name (str): target optional dependency module name.
• this_pkg_name (str | None): your package name shown in hint message.
• extra (str | None): extra name shown as pkg[extra].
• exist_behavior ("skip" | "overwrite" | "error"): behavior when the module was already registered.

exist_behavior semantics

• skip (default): keep old registration.
• overwrite: replace old registration with the new one.
• error: raise RuntimeError.

Notes

• Call optdep.add(...) before importing the optional module.
• This package registers an import hook via sys.meta_path at import time.

License

MIT