Typeguard
This library provides run-time type checking for functions defined with PEP 484 argument (and return) type annotations.
Four principal ways to do type checking are provided, each with its pros and cons:
the
check_argument_types()
andcheck_return_type()
functions:debugger friendly (except when running with the pydev debugger with the C extension installed)
does not work reliably with dynamically defined type hints (e.g. in nested functions)
the
@typechecked
decorator:automatically type checks yields and sends of returned generators (regular and async)
adds an extra frame to the call stack for every call to a decorated function
the stack profiler hook (
with TypeChecker('packagename'):
) (deprecated):emits warnings instead of raising
TypeError
requires very few modifications to the code
multiple TypeCheckers can be stacked/nested
does not work reliably with dynamically defined type hints (e.g. in nested functions)
may cause problems with badly behaving debuggers or profilers
cannot distinguish between an exception being raised and a
None
being returned
the import hook (
typeguard.importhook.install_import_hook()
):automatically annotates classes and functions with
@typechecked
on importno code changes required in target modules
requires imports of modules you need to check to be deferred until after the import hook has been installed
may clash with other import hooks