3.15. Typing Check

  • mypy - the reference implementation for type checkers

  • pyre - written in OCaml and optimized for performance

  • pyright - a type checker that emphasizes speed

  • pytype - checks and infers types for unannotated code

3.15.1. Python

3.15.2. MyPy

$ pip install mypy
$ mypy FILE

Configuration in pyproject.toml file:

[tool.mypy]
# Import discovery
files = ["src"]
namespace_packages = false
explicit_package_bases = false
ignore_missing_imports = false
follow_imports = "normal"
follow_imports_for_stubs = false
no_site_packages = false
no_silence_site_packages = false
# Platform configuration
python_version = "3.10"
platform = "linux-64"
# Disallow dynamic typing
disallow_any_unimported = false # TODO
disallow_any_expr = false # TODO
disallow_any_decorated = false # TODO
disallow_any_explicit = false # TODO
disallow_any_generics = true
disallow_subclassing_any = true
# Untyped definitions and calls
disallow_untyped_calls = true
disallow_untyped_defs = true
disallow_incomplete_defs = true
check_untyped_defs = true
disallow_untyped_decorators = true
# None and Optional handling
no_implicit_optional = true
strict_optional = true
# Configuring warnings
warn_redundant_casts = true
warn_unused_ignores = true
warn_no_return = true
warn_return_any = true
warn_unreachable = false # GH#27396
# Suppressing errors
show_none_errors = true
ignore_errors = false
enable_error_code = "ignore-without-code"
# Miscellaneous strictness flags
allow_untyped_globals = false
allow_redefinition = false
local_partial_types = false
implicit_reexport = true
strict_equality = true
# Configuring error messages
show_error_context = false
show_column_numbers = false
show_error_codes = true

3.15.3. PyType

$ pip install pytype
$ pytype -V 3.11 myfile.py

3.15.4. Pyre