Bump minimum Python type check target version to 3.7 (#15668)

mypy/checkexpr.py

@@ -3072,7 +3072,7 @@ def visit_op_expr(self, e: OpExpr) -> Type:
             # Expressions of form [...] * e get special type inference.
             return self.check_list_multiply(e)
         if e.op == "%":
-            if isinstance(e.left, BytesExpr) and self.chk.options.python_version >= (3, 5):
+            if isinstance(e.left, BytesExpr):
                 return self.strfrm_checker.check_str_interpolation(e.left, e.right)
             if isinstance(e.left, StrExpr):
                 return self.strfrm_checker.check_str_interpolation(e.left, e.right)

mypy/checkstrformat.py

@@ -682,14 +682,6 @@ def check_str_interpolation(self, expr: FormatStringExpr, replacements: Expressi
         self.exprchk.accept(expr)
         specifiers = parse_conversion_specifiers(expr.value)
         has_mapping_keys = self.analyze_conversion_specifiers(specifiers, expr)
-        if isinstance(expr, BytesExpr) and self.chk.options.python_version < (3, 5):
-            self.msg.fail(
-                "Bytes formatting is only supported in Python 3.5 and later",
-                replacements,
-                code=codes.STRING_FORMATTING,
-            )
-            return AnyType(TypeOfAny.from_error)
-
         if has_mapping_keys is None:
             pass  # Error was reported
         elif has_mapping_keys:
@@ -1023,13 +1015,6 @@ def conversion_type(
         NUMERIC_TYPES = NUMERIC_TYPES_NEW if format_call else NUMERIC_TYPES_OLD
         INT_TYPES = REQUIRE_INT_NEW if format_call else REQUIRE_INT_OLD
         if p == "b" and not format_call:
-            if self.chk.options.python_version < (3, 5):
-                self.msg.fail(
-                    'Format character "b" is only supported in Python 3.5 and later',
-                    context,
-                    code=codes.STRING_FORMATTING,
-                )
-                return None
             if not isinstance(expr, BytesExpr):
                 self.msg.fail(
                     'Format character "b" is only supported on bytes patterns',

mypy/defaults.py

@@ -10,7 +10,7 @@
 
 # Earliest Python 3.x version supported via --python-version 3.x. To run
 # mypy, at least version PYTHON3_VERSION is needed.
-PYTHON3_VERSION_MIN: Final = (3, 4)
+PYTHON3_VERSION_MIN: Final = (3, 7)  # Keep in sync with typeshed's python support
 
 CACHE_DIR: Final = ".mypy_cache"
 CONFIG_FILE: Final = ["mypy.ini", ".mypy.ini"]

mypy/messages.py

@@ -1728,7 +1728,6 @@ def need_annotation_for_var(
         self, node: SymbolNode, context: Context, python_version: tuple[int, int] | None = None
     ) -> None:
         hint = ""
-        has_variable_annotations = not python_version or python_version >= (3, 6)
         pep604_supported = not python_version or python_version >= (3, 10)
         # type to recommend the user adds
         recommended_type = None
@@ -1749,18 +1748,10 @@ def need_annotation_for_var(
                     type_dec = f"{type_dec}, {type_dec}"
                 recommended_type = f"{alias}[{type_dec}]"
         if recommended_type is not None:
-            if has_variable_annotations:
-                hint = f' (hint: "{node.name}: {recommended_type} = ...")'
-            else:
-                hint = f' (hint: "{node.name} = ...  # type: {recommended_type}")'
-
-        if has_variable_annotations:
-            needed = "annotation"
-        else:
-            needed = "comment"
+            hint = f' (hint: "{node.name}: {recommended_type} = ...")'
 
         self.fail(
-            f'Need type {needed} for "{unmangle(node.name)}"{hint}',
+            f'Need type annotation for "{unmangle(node.name)}"{hint}',
             context,
             code=codes.VAR_ANNOTATED,
         )

mypy/semanal.py

@@ -2521,12 +2521,7 @@ def visit_import_from(self, imp: ImportFrom) -> None:
                 elif fullname in self.missing_modules:
                     missing_submodule = True
             # If it is still not resolved, check for a module level __getattr__
-            if (
-                module
-                and not node
-                and (module.is_stub or self.options.python_version >= (3, 7))
-                and "__getattr__" in module.names
-            ):
+            if module and not node and "__getattr__" in module.names:
                 # We store the fullname of the original definition so that we can
                 # detect whether two imported names refer to the same thing.
                 fullname = module_id + "." + id
@@ -5446,11 +5441,8 @@ def visit_yield_expr(self, e: YieldExpr) -> None:
                 blocker=True,
             )
         elif self.function_stack[-1].is_coroutine:
-            if self.options.python_version < (3, 6):
-                self.fail('"yield" in async function', e, serious=True, blocker=True)
-            else:
-                self.function_stack[-1].is_generator = True
-                self.function_stack[-1].is_async_generator = True
+            self.function_stack[-1].is_generator = True
+            self.function_stack[-1].is_async_generator = True
         else:
             self.function_stack[-1].is_generator = True
         if e.expr:
@@ -5721,9 +5713,7 @@ def get_module_symbol(self, node: MypyFile, name: str) -> SymbolTableNode | None
                 sym = SymbolTableNode(GDEF, self.modules[fullname])
             elif self.is_incomplete_namespace(module):
                 self.record_incomplete_ref()
-            elif "__getattr__" in names and (
-                node.is_stub or self.options.python_version >= (3, 7)
-            ):
+            elif "__getattr__" in names:
                 gvar = self.create_getattr_var(names["__getattr__"], name, fullname)
                 if gvar:
                     sym = SymbolTableNode(GDEF, gvar)

mypy/semanal_namedtuple.py

@@ -142,9 +142,6 @@ def check_namedtuple_classdef(
           * valid statements
         or None, if any of the types are not ready.
         """
-        if self.options.python_version < (3, 6) and not is_stub_file:
-            self.fail("NamedTuple class syntax is only supported in Python 3.6", defn)
-            return [], [], {}, []
         if len(defn.base_type_exprs) > 1:
             self.fail("NamedTuple should be a single base", defn)
         items: list[str] = []

mypy/semanal_pass1.py

@@ -45,10 +45,9 @@ class SemanticAnalyzerPreAnalysis(TraverserVisitor):
 
       import sys
 
-      def do_stuff():
-          # type: () -> None:
-          if sys.python_version < (3,):
-              import xyz  # Only available in Python 2
+      def do_stuff() -> None:
+          if sys.version_info >= (3, 10):
+              import xyz  # Only available in Python 3.10+
               xyz.whatever()
           ...
 

test-data/unit/README.md

@@ -12,7 +12,7 @@ feature you added. If you added a new `check-*.test` file, it will be autodiscov
 Add the test in this format anywhere in the file:
 
     [case testNewSyntaxBasics]
-    # flags: --python-version 3.6
+    # flags: --python-version 3.10
     x: int
     x = 5
     y: int = 5

test-data/unit/check-async-await.test

@@ -183,7 +183,6 @@ async def f() -> None:
 [typing fixtures/typing-async.pyi]
 
 [case testAsyncForComprehension]
-# flags: --python-version 3.6
 from typing import Generic, Iterable, TypeVar, AsyncIterator, Tuple
 
 T = TypeVar('T')
@@ -223,7 +222,6 @@ async def generatorexp(obj: Iterable[int]):
 [typing fixtures/typing-async.pyi]
 
 [case testAsyncForComprehensionErrors]
-# flags: --python-version 3.6
 from typing import Generic, Iterable, TypeVar, AsyncIterator, Tuple
 
 T = TypeVar('T')
@@ -240,16 +238,10 @@ class asyncify(Generic[T], AsyncIterator[T]):
             raise StopAsyncIteration
 
 async def wrong_iterable(obj: Iterable[int]):
-    [i async for i in obj]
-    [i for i in asyncify(obj)]
-    {i: i async for i in obj}
-    {i: i for i in asyncify(obj)}
-
-[out]
-main:18: error: "Iterable[int]" has no attribute "__aiter__" (not async iterable)
-main:19: error: "asyncify[int]" has no attribute "__iter__"; maybe "__aiter__"? (not iterable)
-main:20: error: "Iterable[int]" has no attribute "__aiter__" (not async iterable)
-main:21: error: "asyncify[int]" has no attribute "__iter__"; maybe "__aiter__"? (not iterable)
+    [i async for i in obj]  # E: "Iterable[int]" has no attribute "__aiter__" (not async iterable)
+    [i for i in asyncify(obj)]  # E: "asyncify[int]" has no attribute "__iter__"; maybe "__aiter__"? (not iterable)
+    {i: i async for i in obj}  # E: "Iterable[int]" has no attribute "__aiter__" (not async iterable)
+    {i: i for i in asyncify(obj)}  # E: "asyncify[int]" has no attribute "__iter__"; maybe "__aiter__"? (not iterable)
 [builtins fixtures/async_await.pyi]
 [typing fixtures/typing-async.pyi]
 
@@ -340,17 +332,6 @@ async def f() -> None:
 [builtins fixtures/async_await.pyi]
 [typing fixtures/typing-async.pyi]
 
-[case testNoYieldInAsyncDef]
-# flags: --python-version 3.5
-
-async def f():
-    yield None  # E: "yield" in async function
-async def g():
-    yield  # E: "yield" in async function
-async def h():
-    x = yield  # E: "yield" in async function
-[builtins fixtures/async_await.pyi]
-
 [case testNoYieldFromInAsyncDef]
 
 async def f():
@@ -422,7 +403,6 @@ def f() -> Generator[int, str, int]:
 -- ---------------------------------------------------------------------
 
 [case testAsyncGenerator]
-# flags: --python-version 3.6
 from typing import AsyncGenerator, Generator
 
 async def f() -> int:
@@ -450,7 +430,6 @@ async def wrong_return() -> Generator[int, None, None]:  # E: The return type of
 [typing fixtures/typing-async.pyi]
 
 [case testAsyncGeneratorReturnIterator]
-# flags: --python-version 3.6
 from typing import AsyncIterator
 
 async def gen() -> AsyncIterator[int]:
@@ -466,7 +445,6 @@ async def use_gen() -> None:
 [typing fixtures/typing-async.pyi]
 
 [case testAsyncGeneratorManualIter]
-# flags: --python-version 3.6
 from typing import AsyncGenerator
 
 async def genfunc() -> AsyncGenerator[int, None]:
@@ -484,7 +462,6 @@ async def user() -> None:
 [typing fixtures/typing-async.pyi]
 
 [case testAsyncGeneratorAsend]
-# flags: --python-version 3.6
 from typing import AsyncGenerator
 
 async def f() -> None:
@@ -505,7 +482,6 @@ async def h() -> None:
 [typing fixtures/typing-async.pyi]
 
 [case testAsyncGeneratorAthrow]
-# flags: --python-version 3.6
 from typing import AsyncGenerator
 
 async def gen() -> AsyncGenerator[str, int]:
@@ -524,25 +500,20 @@ async def h() -> None:
 [typing fixtures/typing-async.pyi]
 
 [case testAsyncGeneratorNoSyncIteration]
-# flags: --python-version 3.6
 from typing import AsyncGenerator
 
 async def gen() -> AsyncGenerator[int, None]:
     for i in [1, 2, 3]:
         yield i
 
 def h() -> None:
-    for i in gen():
+    for i in gen():  # E: "AsyncGenerator[int, None]" has no attribute "__iter__"; maybe "__aiter__"? (not iterable)
         pass
 
 [builtins fixtures/dict.pyi]
 [typing fixtures/typing-async.pyi]
 
-[out]
-main:9: error: "AsyncGenerator[int, None]" has no attribute "__iter__"; maybe "__aiter__"? (not iterable)
-
 [case testAsyncGeneratorNoYieldFrom]
-# flags: --python-version 3.6
 from typing import AsyncGenerator
 
 async def f() -> AsyncGenerator[int, None]:
@@ -555,7 +526,6 @@ async def gen() -> AsyncGenerator[int, None]:
 [typing fixtures/typing-async.pyi]
 
 [case testAsyncGeneratorNoReturnWithValue]
-# flags: --python-version 3.6
 from typing import AsyncGenerator
 
 async def return_int() -> AsyncGenerator[int, None]: