Merge branch 'master' into master

Author: charulatalodha

docs/source/command_line.rst

@@ -593,12 +593,58 @@ of the above sections.
     This flag causes mypy to suppress errors caused by not being able to fully
     infer the types of global and class variables.
 
-.. option:: --allow-redefinition
+.. option:: --allow-redefinition-new
 
     By default, mypy won't allow a variable to be redefined with an
-    unrelated type. This flag enables redefinition of a variable with an
+    unrelated type. This *experimental* flag enables the redefinition of
+    unannotated variables with an arbitrary type. You will also need to enable
+    :option:`--local-partial-types <mypy --local-partial-types>`.
+    Example:
+
+    .. code-block:: python
+
+        def maybe_convert(n: int, b: bool) -> int | str:
+            if b:
+                x = str(n)  # Assign "str"
+            else:
+                x = n       # Assign "int"
+            # Type of "x" is "int | str" here.
+            return x
+
+    Without the new flag, mypy only supports inferring optional types
+    (``X | None``) from multiple assignments. With this option enabled,
+    mypy can infer arbitrary union types.
+
+    This also enables an unannotated variable to have different types in different
+    code locations:
+
+    .. code-block:: python
+
+        if check():
+            for x in range(n):
+                # Type of "x" is "int" here.
+                ...
+        else:
+            for x in ['a', 'b']:
+                # Type of "x" is "str" here.
+                ...
+
+    Note: We are planning to turn this flag on by default in a future mypy
+    release, along with :option:`--local-partial-types <mypy --local-partial-types>`.
+    The feature is still experimental, and the semantics may still change.
+
+.. option:: --allow-redefinition
+
+    This is an older variant of
+    :option:`--allow-redefinition-new <mypy --allow-redefinition-new>`.
+    This flag enables redefinition of a variable with an
     arbitrary type *in some contexts*: only redefinitions within the
     same block and nesting depth as the original definition are allowed.
+
+    We have no plans to remove this flag, but we expect that
+    :option:`--allow-redefinition-new <mypy --allow-redefinition-new>`
+    will replace this flag for new use cases eventually.
+
     Example where this can be useful:
 
     .. code-block:: python

docs/source/config_file.rst

@@ -713,6 +713,44 @@ section of the command line docs.
     Causes mypy to suppress errors caused by not being able to fully
     infer the types of global and class variables.
 
+.. confval:: allow_redefinition_new
+
+    :type: boolean
+    :default: False
+
+    By default, mypy won't allow a variable to be redefined with an
+    unrelated type. This *experimental* flag enables the redefinition of
+    unannotated variables with an arbitrary type. You will also need to enable
+    :confval:`local_partial_types`.
+    Example:
+
+    .. code-block:: python
+
+        def maybe_convert(n: int, b: bool) -> int | str:
+            if b:
+                x = str(n)  # Assign "str"
+            else:
+                x = n       # Assign "int"
+            # Type of "x" is "int | str" here.
+            return x
+
+    This also enables an unannotated variable to have different types in different
+    code locations:
+
+    .. code-block:: python
+
+        if check():
+            for x in range(n):
+                # Type of "x" is "int" here.
+                ...
+        else:
+            for x in ['a', 'b']:
+                # Type of "x" is "str" here.
+                ...
+
+    Note: We are planning to turn this flag on by default in a future mypy
+    release, along with :confval:`local_partial_types`.
+
 .. confval:: allow_redefinition
 
     :type: boolean
@@ -746,6 +784,7 @@ section of the command line docs.
 
     Disallows inferring variable type for ``None`` from two assignments in different scopes.
     This is always implicitly enabled when using the :ref:`mypy daemon <mypy_daemon>`.
+    This will be enabled by default in a future mypy release.
 
 .. confval:: disable_error_code
 

mypy/join.py

@@ -635,6 +635,8 @@ def default(self, typ: Type) -> ProperType:
         typ = get_proper_type(typ)
         if isinstance(typ, Instance):
             return object_from_instance(typ)
+        elif isinstance(typ, TypeType):
+            return self.default(typ.item)
         elif isinstance(typ, UnboundType):
             return AnyType(TypeOfAny.special_form)
         elif isinstance(typ, TupleType):

mypy/plugins/default.py

@@ -316,7 +316,7 @@ def typed_dict_pop_callback(ctx: MethodContext) -> Type:
 
         value_types = []
         for key in keys:
-            if key in ctx.type.required_keys:
+            if key in ctx.type.required_keys or key in ctx.type.readonly_keys:
                 ctx.api.msg.typeddict_key_cannot_be_deleted(ctx.type, key, key_expr)
 
             value_type = ctx.type.items.get(key)

mypy/test/testtypes.py

@@ -1064,6 +1064,10 @@ def test_variadic_tuple_joins(self) -> None:
             self.tuple(UnpackType(Instance(self.fx.std_tuplei, [self.fx.a])), self.fx.a),
         )
 
+    def test_join_type_type_type_var(self) -> None:
+        self.assert_join(self.fx.type_a, self.fx.t, self.fx.o)
+        self.assert_join(self.fx.t, self.fx.type_a, self.fx.o)
+
     # There are additional test cases in check-inference.test.
 
     # TODO: Function types + varargs and default args.

mypy/version.py

@@ -8,7 +8,7 @@
 # - Release versions have the form "1.2.3".
 # - Dev versions have the form "1.2.3+dev" (PLUS sign to conform to PEP 440).
 # - Before 1.0 we had the form "0.NNN".
-__version__ = "1.16.0+dev"
+__version__ = "1.17.0+dev"
 base_version = __version__
 
 mypy_dir = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))

mypyc/codegen/emitmodule.py

@@ -867,8 +867,16 @@ def generate_globals_init(self, emitter: Emitter) -> None:
 
     def generate_module_def(self, emitter: Emitter, module_name: str, module: ModuleIR) -> None:
         """Emit the PyModuleDef struct for a module and the module init function."""
-        # Emit module methods
         module_prefix = emitter.names.private_name(module_name)
+        self.emit_module_exec_func(emitter, module_name, module_prefix, module)
+        self.emit_module_methods(emitter, module_name, module_prefix, module)
+        self.emit_module_def_struct(emitter, module_name, module_prefix)
+        self.emit_module_init_func(emitter, module_name, module_prefix)
+
+    def emit_module_methods(
+        self, emitter: Emitter, module_name: str, module_prefix: str, module: ModuleIR
+    ) -> None:
+        """Emit module methods (the static PyMethodDef table)."""
         emitter.emit_line(f"static PyMethodDef {module_prefix}module_methods[] = {{")
         for fn in module.functions:
             if fn.class_name is not None or fn.name == TOP_LEVEL_NAME:
@@ -888,7 +896,10 @@ def generate_module_def(self, emitter: Emitter, module_name: str, module: Module
         emitter.emit_line("};")
         emitter.emit_line()
 
-        # Emit module definition struct
+    def emit_module_def_struct(
+        self, emitter: Emitter, module_name: str, module_prefix: str
+    ) -> None:
+        """Emit the static module definition struct (PyModuleDef)."""
         emitter.emit_lines(
             f"static struct PyModuleDef {module_prefix}module = {{",
             "PyModuleDef_HEAD_INIT,",
@@ -900,36 +911,22 @@ def generate_module_def(self, emitter: Emitter, module_name: str, module: Module
             "};",
         )
         emitter.emit_line()
-        # Emit module init function. If we are compiling just one module, this
-        # will be the C API init function. If we are compiling 2+ modules, we
-        # generate a shared library for the modules and shims that call into
-        # the shared library, and in this case we use an internal module
-        # initialized function that will be called by the shim.
-        if not self.use_shared_lib:
-            declaration = f"PyMODINIT_FUNC PyInit_{module_name}(void)"
-        else:
-            declaration = f"PyObject *CPyInit_{exported_name(module_name)}(void)"
-        emitter.emit_lines(declaration, "{")
-        emitter.emit_line("PyObject* modname = NULL;")
-        # Store the module reference in a static and return it when necessary.
-        # This is separate from the *global* reference to the module that will
-        # be populated when it is imported by a compiled module. We want that
-        # reference to only be populated when the module has been successfully
-        # imported, whereas this we want to have to stop a circular import.
-        module_static = self.module_internal_static_name(module_name, emitter)
 
-        emitter.emit_lines(
-            f"if ({module_static}) {{",
-            f"Py_INCREF({module_static});",
-            f"return {module_static};",
-            "}",
-        )
+    def emit_module_exec_func(
+        self, emitter: Emitter, module_name: str, module_prefix: str, module: ModuleIR
+    ) -> None:
+        """Emit the module init function.
 
-        emitter.emit_lines(
-            f"{module_static} = PyModule_Create(&{module_prefix}module);",
-            f"if (unlikely({module_static} == NULL))",
-            "    goto fail;",
-        )
+        If we are compiling just one module, this will be the C API init
+        function. If we are compiling 2+ modules, we generate a shared
+        library for the modules and shims that call into the shared
+        library, and in this case we use an internal module initialized
+        function that will be called by the shim.
+        """
+        declaration = f"static int {module_prefix}_exec(PyObject *module)"
+        module_static = self.module_internal_static_name(module_name, emitter)
+        emitter.emit_lines(declaration, "{")
+        emitter.emit_line("PyObject* modname = NULL;")
         emitter.emit_line(
             f'modname = PyObject_GetAttrString((PyObject *){module_static}, "__name__");'
         )
@@ -959,8 +956,9 @@ def generate_module_def(self, emitter: Emitter, module_name: str, module: Module
 
         emitter.emit_lines("Py_DECREF(modname);")
 
-        emitter.emit_line(f"return {module_static};")
-        emitter.emit_lines("fail:", f"Py_CLEAR({module_static});", "Py_CLEAR(modname);")
+        emitter.emit_line("return 0;")
+        emitter.emit_lines("fail:")
+        emitter.emit_lines(f"Py_CLEAR({module_static});", "Py_CLEAR(modname);")
         for name, typ in module.final_names:
             static_name = emitter.static_name(name, module_name)
             emitter.emit_dec_ref(static_name, typ, is_xdec=True)
@@ -970,9 +968,44 @@ def generate_module_def(self, emitter: Emitter, module_name: str, module: Module
         # so we have to decref them
         for t in type_structs:
             emitter.emit_line(f"Py_CLEAR({t});")
-        emitter.emit_line("return NULL;")
+        emitter.emit_line("return -1;")
         emitter.emit_line("}")
 
+    def emit_module_init_func(
+        self, emitter: Emitter, module_name: str, module_prefix: str
+    ) -> None:
+        if not self.use_shared_lib:
+            declaration = f"PyMODINIT_FUNC PyInit_{module_name}(void)"
+        else:
+            declaration = f"PyObject *CPyInit_{exported_name(module_name)}(void)"
+        emitter.emit_lines(declaration, "{")
+
+        exec_func = f"{module_prefix}_exec"
+
+        # Store the module reference in a static and return it when necessary.
+        # This is separate from the *global* reference to the module that will
+        # be populated when it is imported by a compiled module. We want that
+        # reference to only be populated when the module has been successfully
+        # imported, whereas this we want to have to stop a circular import.
+        module_static = self.module_internal_static_name(module_name, emitter)
+
+        emitter.emit_lines(
+            f"if ({module_static}) {{",
+            f"Py_INCREF({module_static});",
+            f"return {module_static};",
+            "}",
+        )
+
+        emitter.emit_lines(
+            f"{module_static} = PyModule_Create(&{module_prefix}module);",
+            f"if (unlikely({module_static} == NULL))",
+            "    goto fail;",
+        )
+        emitter.emit_lines(f"if ({exec_func}({module_static}) != 0)", "    goto fail;")
+        emitter.emit_line(f"return {module_static};")
+        emitter.emit_lines("fail:", "return NULL;")
+        emitter.emit_lines("}")
+
     def generate_top_level_call(self, module: ModuleIR, emitter: Emitter) -> None:
         """Generate call to function representing module top level."""
         # Optimization: we tend to put the top level last, so reverse iterate