- --check-untyped-def
- --strict
Type in unannotated function
examples/python-types-at-pyweb-2025-01/unannotated_function.py
def do_something(): answer :str = 42 print(answer) do_something()
$ mypy unannotated_function.py unannotated_function.py:3:5: note: By default the bodies of untyped functions are not checked, consider using --check-untyped-defs [annotation-unchecked] Success: no issues found in 1 source file $ mypy --check-untyped-def unannotated_function.py unannotated_function.py:3:19: error: Incompatible types in assignment (expression has type "int", variable has type "str") [assignment] Found 1 error in 1 file (checked 1 source file) $ mypy --strict unannotated_function.py unannotated_function.py:2:1: error: Function is missing a return type annotation [no-untyped-def] unannotated_function.py:2:1: note: Use "-> None" if function does not return a value unannotated_function.py:3:19: error: Incompatible types in assignment (expression has type "int", variable has type "str") [assignment] unannotated_function.py:6:1: error: Call to untyped function "do_something" in typed context [no-untyped-call] Found 3 errors in 1 file (checked 1 source file)