Mypy Extensions

mypy-extensions provides specific type system extensions for programs checked with the mypy type checker and the mypyc compiler. It acts as a bridge for experimental or mypy-specific typing features that may eventually be standardized in Python's `typing` module or `typing_extensions`, but are supported early by mypy. The library follows mypy's active development and releases are tied to mypy's needs, which typically sees multiple releases per month for the main mypy project.