gh-133117: Run mypy on tomllib in CI

Author: sobolevn

.github/workflows/mypy.yml

@@ -9,6 +9,7 @@ on:
     paths:
       - ".github/workflows/mypy.yml"
       - "Lib/_pyrepl/**"
+      - "Lib/tomllib/**"
       - "Lib/test/libregrtest/**"
       - "Tools/build/generate_sbom.py"
       - "Tools/cases_generator/**"
@@ -41,6 +42,7 @@ jobs:
       matrix:
         target: [
           "Lib/_pyrepl",
+          "Lib/tomllib",
           "Lib/test/libregrtest",
           "Tools/build",
           "Tools/cases_generator",

Lib/tomllib/_parser.py

@@ -214,7 +214,7 @@ class Flags:
     EXPLICIT_NEST = 1
 
     def __init__(self) -> None:
-        self._flags: dict[str, dict] = {}
+        self._flags: dict[str, dict[Any, Any]] = {}
         self._pending_flags: set[tuple[Key, int]] = set()
 
     def add_pending(self, key: Key, flag: int) -> None:
@@ -272,8 +272,8 @@ def get_or_create_nest(
         key: Key,
         *,
         access_lists: bool = True,
-    ) -> dict:
-        cont: Any = self.dict
+    ) -> dict[str, Any]:
+        cont = self.dict
         for k in key:
             if k not in cont:
                 cont[k] = {}
@@ -486,9 +486,9 @@ def parse_one_line_basic_str(src: str, pos: Pos) -> tuple[Pos, str]:
     return parse_basic_str(src, pos, multiline=False)
 
 
-def parse_array(src: str, pos: Pos, parse_float: ParseFloat) -> tuple[Pos, list]:
+def parse_array(src: str, pos: Pos, parse_float: ParseFloat) -> tuple[Pos, list[Any]]:
     pos += 1
-    array: list = []
+    array: list[Any] = []
 
     pos = skip_comments_and_array_ws(src, pos)
     if src.startswith("]", pos):
@@ -510,7 +510,7 @@ def parse_array(src: str, pos: Pos, parse_float: ParseFloat) -> tuple[Pos, list]
             return pos + 1, array
 
 
-def parse_inline_table(src: str, pos: Pos, parse_float: ParseFloat) -> tuple[Pos, dict]:
+def parse_inline_table(src: str, pos: Pos, parse_float: ParseFloat) -> tuple[Pos, dict[str, Any]]:
     pos += 1
     nested_dict = NestedDict()
     flags = Flags()
@@ -741,7 +741,7 @@ def make_safe_parse_float(parse_float: ParseFloat) -> ParseFloat:
     instead of returning illegal types.
     """
     # The default `float` callable never returns illegal types. Optimize it.
-    if parse_float is float:  # type: ignore[comparison-overlap]
+    if parse_float is float:
         return float
 
     def safe_parse_float(float_str: str) -> Any:

Lib/tomllib/_re.py

@@ -52,7 +52,7 @@
 )
 
 
-def match_to_datetime(match: re.Match) -> datetime | date:
+def match_to_datetime(match: re.Match[str]) -> datetime | date:
     """Convert a `RE_DATETIME` match to `datetime.datetime` or `datetime.date`.
 
     Raises ValueError if the match does not correspond to a valid date
@@ -101,13 +101,13 @@ def cached_tz(hour_str: str, minute_str: str, sign_str: str) -> timezone:
     )
 
 
-def match_to_localtime(match: re.Match) -> time:
+def match_to_localtime(match: re.Match[str]) -> time:
     hour_str, minute_str, sec_str, micros_str = match.groups()
     micros = int(micros_str.ljust(6, "0")) if micros_str else 0
     return time(int(hour_str), int(minute_str), int(sec_str), micros)
 
 
-def match_to_number(match: re.Match, parse_float: ParseFloat) -> Any:
+def match_to_number(match: re.Match[str], parse_float: ParseFloat) -> Any:
     if match.group("floatpart"):
         return parse_float(match.group())
     return int(match.group(), 0)

Lib/tomllib/mypy.ini

@@ -0,0 +1,16 @@
+# Config file for running mypy on tomllib.
+# Run mypy by invoking `mypy --config-file Lib/tomllib/mypy.ini`
+# on the command-line from the repo root
+
+[mypy]
+files = Lib/tomllib
+mypy_path = $MYPY_CONFIG_FILE_DIR/../../Misc/mypy
+explicit_package_bases = True
+python_version = 3.12
+pretty = True
+
+# Enable most stricter settings
+enable_error_code = ignore-without-code
+strict = True
+strict_bytes = True
+local_partial_types = True

Misc/mypy/tomllib

@@ -0,0 +1 @@
+../../Lib/tomllib

Misc/mypy/typed-stdlib.txt

@@ -2,3 +2,4 @@
 
 _colorize.py
 _pyrepl
+tomllib