Merge branch 'master' into fix_strict_quality_in_loops

Author: tyralla

.github/workflows/mypy_primer.yml

@@ -39,7 +39,7 @@ jobs:
           persist-credentials: false
       - uses: actions/setup-python@v5
         with:
-          python-version: "3.13"
+          python-version: "3.14"
       - name: Install dependencies
         run: |
           python -m pip install -U pip

.github/workflows/test.yml

@@ -95,6 +95,18 @@ jobs:
         #   tox_extra_args: "-n 4 mypyc/test/test_run.py mypyc/test/test_external.py"
         #   debug_build: true
 
+        - name: Parallel tests with py314-ubuntu, interpreted
+          python: '3.14'
+          os: ubuntu-24.04-arm
+          toxenv: py
+          tox_extra_args: "-n 4 --mypy-num-workers=4 mypy/test/testcheck.py"
+        - name: Parallel tests with py314-ubuntu, mypyc-compiled
+          python: '3.14'
+          os: ubuntu-24.04-arm
+          toxenv: py
+          tox_extra_args: "-n 4 --mypy-num-workers=4 mypy/test/testcheck.py"
+          test_mypyc: true
+
         - name: Type check our own code (py310-ubuntu)
           python: '3.10'
           os: ubuntu-latest

docs/source/error_code_list.rst

@@ -1151,6 +1151,25 @@ Warn about cases where a bytes object may be converted to a string in an unexpec
     print(f"The alphabet starts with {b!r}")  # The alphabet starts with b'abc'
     print(f"The alphabet starts with {b.decode('utf-8')}")  # The alphabet starts with abc
 
+.. _code-str-unpack:
+
+Check that ``str`` is not unpacked [str-unpack]
+---------------------------------------------------------
+
+It can sometimes be surprising that ``str`` is iterable, especially when unpacking
+in an assignment.
+
+Example:
+
+.. code-block:: python
+
+    def print_dict(d: dict[str, str]) -> int:
+        # We meant to do d.items(), but instead we're unpacking the str keys of d
+
+        # Error: Unpacking a string is disallowed
+        for k, v in d:
+            print(k, v)
+
 .. _code-overload-overlap:
 
 Check that overloaded functions don't overlap [overload-overlap]

misc/analyze_cache.py

@@ -7,8 +7,7 @@
 import os.path
 from collections import Counter
 from collections.abc import Iterable
-from typing import Any, Final
-from typing_extensions import TypeAlias as _TypeAlias
+from typing import Any, Final, TypeAlias as _TypeAlias
 
 ROOT: Final = ".mypy_cache/3.5"
 

misc/incremental_checker.py

@@ -44,8 +44,7 @@
 import textwrap
 import time
 from argparse import ArgumentParser, Namespace, RawDescriptionHelpFormatter
-from typing import Any, Final
-from typing_extensions import TypeAlias as _TypeAlias
+from typing import Any, Final, TypeAlias as _TypeAlias
 
 CACHE_PATH: Final = ".incremental_checker_cache.json"
 MYPY_REPO_URL: Final = "https://github.com/python/mypy.git"

misc/perf_checker.py

@@ -8,7 +8,7 @@
 import subprocess
 import textwrap
 import time
-from typing import Callable
+from collections.abc import Callable
 
 
 class Command:

mypy/api.py

@@ -46,8 +46,9 @@
 from __future__ import annotations
 
 import sys
+from collections.abc import Callable
 from io import StringIO
-from typing import Callable, TextIO
+from typing import TextIO
 
 
 def _run(main_wrapper: Callable[[TextIO, TextIO], None]) -> tuple[str, str, int]:

mypy/applytype.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
-from collections.abc import Iterable, Sequence
-from typing import Callable
+from collections.abc import Callable, Iterable, Sequence
 
 import mypy.subtypes
 from mypy.erasetype import erase_typevars

mypy/argmap.py

@@ -2,8 +2,8 @@
 
 from __future__ import annotations
 
-from collections.abc import Sequence
-from typing import TYPE_CHECKING, Callable
+from collections.abc import Callable, Sequence
+from typing import TYPE_CHECKING
 
 from mypy import nodes
 from mypy.maptype import map_instance_to_supertype
@@ -36,8 +36,8 @@ def map_actuals_to_formals(
     The result contains a list of caller argument indexes mapping to each
     callee argument index, indexed by callee index.
 
-    The caller_arg_type argument should evaluate to the type of the actual
-    argument type with the given index.
+    The actual_arg_type argument should evaluate to the type of the actual
+    argument with the given index.
     """
     nformals = len(formal_kinds)
     formal_to_actual: list[list[int]] = [[] for i in range(nformals)]

mypy/binder.py

@@ -3,8 +3,7 @@
 from collections import defaultdict
 from collections.abc import Iterator
 from contextlib import contextmanager
-from typing import NamedTuple
-from typing_extensions import TypeAlias as _TypeAlias
+from typing import NamedTuple, TypeAlias as _TypeAlias
 
 from mypy.erasetype import remove_instance_last_known_values
 from mypy.literals import Key, extract_var_from_literal_hash, literal, literal_hash, subkeys