python bindings: enable mypy --strict

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>

contrib/bindings/python/mypy.ini

@@ -0,0 +1,2 @@
+[mypy]
+strict = true

contrib/bindings/python/pathrs/_pathrs.py

@@ -24,7 +24,8 @@
 import fcntl
 
 import typing
-from typing import Any, IO, Optional, TextIO, Type, TypeVar, Union
+from types import TracebackType
+from typing import Any, Dict, IO, Optional, TextIO, Type, TypeVar, Union
 
 # TODO: Remove this once we only support Python >= 3.11.
 from typing_extensions import Self, TypeAlias
@@ -88,7 +89,7 @@ class Error(Exception):
  errno: Optional[int]
  strerror: Optional[str]
 
- def __init__(self, message: str, *_, errno: Optional[int] = None):
+ def __init__(self, message: str, *, errno: Optional[int] = None):
  # Construct Exception.
  super().__init__(message)
 
@@ -110,7 +111,7 @@ def _fetch(cls, err_id: int) -> Optional[Self]:
  return None
 
  err = libpathrs_so.pathrs_errorinfo(err_id)
- if err == ffi.NULL:
+ if err == ffi.NULL: # type: ignore # TODO: Make this check nicer...
  return None
 
  description = _pystr(err.description)
@@ -249,7 +250,7 @@ def fdopen(self, mode: str = "r") -> IO[Any]:
  raise
 
  @classmethod
- def from_raw_fd(cls, fd: int) -> Self:
+ def from_raw_fd(cls: Type[Fd], fd: int) -> Fd:
  "Shorthand for WrappedFd(fd)."
  return cls(fd)
 
@@ -300,7 +301,7 @@ def __copy__(self) -> Self:
  # A "shallow copy" of a file is the same as a deep copy.
  return copy.deepcopy(self)
 
- def __deepcopy__(self, memo) -> Self:
+ def __deepcopy__(self, memo: Dict[int, Any]) -> Self:
  "Identical to WrappedFd.clone()"
  return self.clone()
 
@@ -311,7 +312,12 @@ def __del__(self) -> None:
  def __enter__(self) -> Self:
  return self
 
- def __exit__(self, exc_type, exc_value, exc_traceback) -> None:
+ def __exit__(
+ self,
+ exc_type: Optional[Type[BaseException]],
+ exc_value: Optional[BaseException],
+ exc_traceback: Optional[TracebackType],
+ ) -> None:
  self.close()
 
 
@@ -442,7 +448,8 @@ def proc_readlink(base: ProcfsBase, path: str) -> str:
  if n < 0:
  raise Error._fetch(n) or INTERNAL_ERROR
  elif n <= linkbuf_size:
- return ffi.buffer(linkbuf, linkbuf_size)[:n].decode("latin1")
+ buf = typing.cast(bytes, ffi.buffer(linkbuf, linkbuf_size)[:n])
+ return buf.decode("latin1")
  else:
  # The contents were truncated. Unlike readlinkat, pathrs returns
  # the size of the link when it checked. So use the returned size
@@ -551,7 +558,8 @@ def readlink(self, path: str) -> str:
  if n < 0:
  raise Error._fetch(n) or INTERNAL_ERROR
  elif n <= linkbuf_size:
- return ffi.buffer(linkbuf, linkbuf_size)[:n].decode("latin1")
+ buf = typing.cast(bytes, ffi.buffer(linkbuf, linkbuf_size)[:n])
+ return buf.decode("latin1")
  else:
  # The contents were truncated. Unlike readlinkat, pathrs returns
  # the size of the link when it checked. So use the returned size

contrib/bindings/python/pathrs/pathrs_build.py

@@ -23,7 +23,7 @@
 import os
 import sys
 
-from typing import Optional
+from typing import Any, Optional
 from collections.abc import Iterable
 
 import cffi
@@ -51,7 +51,7 @@ def load_hdr(ffi: cffi.FFI, hdr_path: str) -> None:
  ffi.cdef(hdr)
 
 
-def create_ffibuilder(**kwargs) -> cffi.FFI:
+def create_ffibuilder(**kwargs: Any) -> cffi.FFI:
  ffibuilder = cffi.FFI()
  ffibuilder.cdef("typedef uint32_t dev_t;")
 

contrib/bindings/python/setup.py

@@ -17,16 +17,18 @@
 
 import setuptools
 
+from typing import Any, Dict
+
 
 # This is only needed for backwards compatibility with older versions.
-def parse_pyproject():
+def parse_pyproject() -> Dict[str, Any]:
  try:
  import tomllib
 
  openmode = "rb"
  except ImportError:
  # TODO: Remove this once we only support Python >= 3.11.
- import toml as tomllib
+ import toml as tomllib # type: ignore
 
  openmode = "r"