Sometimes, MyPy will complains that it cannot do typechecks for installed package.
… error: Cannot find implementation or library stub for module named ‘…’
See also Missing imports in the MyPu docs.
Missing type hints for built-in module
- Update and rerun MyPy.
- File a bug report.
Missing type hints for third party library
If the package you installed does not have type annotations built in, then you can do one of the following.
- Upgrade the package.
- Find stubs that someone wrote for the package and has shared.
- Write your own, at least just for the portion of the package that you need.
- Add an ignore configuration.
Read on below to see those in more detail.
Upgrade the version of the library you’re using, in case a newer version has started to include type hints.
Search to see if there is a PEP 561 compliant stub package, corresponding to your third party library.
Stub packages let you install type hints independently from the library itself.
For example, if you want type hints for the
djangolibrary, you can install the
Write your own stub files containing type hints for the library.
You can point mypy at your type hints either by passing them in via the command line, by using the files or mypy_path config file options, or by adding the location to the MYPYPATH environment variable.
These stub files do not need to be complete! A good strategy is to use stubgen, a program that comes bundled with mypy, to generate a first rough draft of the stubs. You can then iterate on just the parts of the library you need.
- stubgen in the MyPy docs
With MyPy installed, you can run:
It will generate
out/foo.pyi. You should place this in the same directory as the script.
See also these to to automatically annotate legacy code, according to the docs:
Configure to ignore
- To suppress a single missing import error, add this at the end of the line containing the import:
import foo # type: ignore
Handle multi-line import. Note putting the comment after closing bracket doesn’t work.
from foo.bar import ( # type: ignore FIZZ, BUZZ )
- Add to your MyPy Config file for package
[mypy-foo.*] ignore_missing_imports = True
[mypy-foo] ignore_missing_imports = True
- Ignore across libraries:
[mypy] ignore_missing_imports = True