Remove Python 3.6 branches from typeshed

[AlexWaygood]

The first commit here was done using the following script:

Details

#!/usr/bin/env python3importastimportsubprocessimportsysfromcollectionsimportCounterfromcollections.abcimportIteratorfromcontextlibimportcontextmanagerfromdataclassesimportdataclassfromitertoolsimportchainfrompathlibimportPath@dataclassclassNestingCounter:
nesting: int=0@contextmanagerdefenabled(self) ->Iterator[None]:
self.nesting+=1try:
yieldfinally:
self.nesting-=1@propertydefactive(self) ->bool:
"""Determine whether the level of nesting is currently non-zero"""returnbool(self.nesting)
deffix_bad_syntax(path: Path) ->None:
withopen(path) asf:
stub=f.read()
lines=dict(enumerate(stub.splitlines()))
tree=ast.parse(stub)
lines_to_delete: list[int] = []
classOldSyntaxReplacer(ast.NodeVisitor):
def__init__(self) ->None:
self.visiting_orelse=NestingCounter()
self.visiting_class=NestingCounter()
self.single_statement_class=Falseself.class_stmt_has_orelse=False@staticmethoddefget_linenos(node: ast.AST) ->tuple[int, int]:
lineno, end_lineno=node.lineno, node.end_linenoassertisinstance(lineno, int)
assertisinstance(end_lineno, int)
returnlineno, end_linenodefdelete_node(self, node: ast.AST, *, first_line_only: bool=False) ->None:
lineno, end_lineno=self.get_linenos(node)
ifisinstance(node, (ast.FunctionDef, ast.AsyncFunctionDef)):
lineno-=len(node.decorator_list)
ifself.visiting_class.activeandself.single_statement_classandnotself.class_stmt_has_orelse:
lines[lineno-2] +=' ...'iffirst_line_only:
lines_to_delete.append(lineno-1)
else:
lines_to_delete.extend(range(lineno-1, end_lineno))
defvisit_ClassDef(self, node: ast.ClassDef) ->None:
old_val=self.single_statement_classiflen(node.body) ==1:
self.single_statement_class=Trueclass_stmt_node=node.body[0]
ifisinstance(class_stmt_node, ast.If):
self.class_stmt_has_orelse=bool(class_stmt_node.orelse)
withself.visiting_class.enabled():
self.generic_visit(node)
self.single_statement_class=old_valdefvisit_If(self, node: ast.If) ->None:
test, body, orelse=node.test, node.body, node.orelseifisinstance(test, ast.Compare):
ifnotast.unparse(test).startswith("sys.version_info "):
self.generic_visit(node)
elifast.unparse(test) =="sys.version_info < (3, 7)":
returnself.delete_node(node)
elifast.unparse(test) =="sys.version_info >= (3, 7)":
ifself.visiting_orelse.active:
lines[node.lineno] =lines[node.lineno].replace("elif sys.version_info >= (3, 7):", "else:")
else:
self.delete_node(node, first_line_only=True)
ifbody:
start, _=self.get_linenos(test)
_, end=self.get_linenos(body[-1])
forlinenoinrange(start, end):
lines[lineno] =lines[lineno][4:]
iforelse:
_, lineno_to_delete=self.get_linenos(body[-1])
line=lines[lineno_to_delete]
whileline.strip() !="else:":
lineno_to_delete+=1line=lines[lineno_to_delete]
lines_to_delete.append(lineno_to_delete)
forchildinorelse:
self.delete_node(child)
forchildinbody:
self.generic_visit(child)
else:
forchildinbody:
self.generic_visit(child)
withself.visiting_orelse.enabled():
forchildinorelse:
self.generic_visit(child)
else:
self.generic_visit(node)
OldSyntaxReplacer().visit(tree)
ifnotlines_to_delete:
returnforlinenoinlines_to_delete:
try:
dellines[lineno]
exceptKeyError:
continuenew_stub='\n'.join(lines.values())
try:
new_tree=ast.parse(new_stub)
except:
print('OLD\n\n')
print('\n'.join(stub.splitlines()[140:150]))
print('\n\nNEW\n\n')
print('\n'.join(new_stub.splitlines()[140:150]))
raisenames_count: Counter[str] =Counter()
classNameFinder(ast.NodeVisitor):
defvisit_Name(self, node: ast.Name) ->None:
names_count[node.id] +=1NameFinder().visit(new_tree)
ifnames_count["sys"] ==1:
fornodeinnew_tree.body:
ifisinstance(node, ast.Import) andnode.names[0].name=="sys":
dellines[node.lineno-1]
new_stub='\n'.join(lines.values())
breakwithopen(path, "w") asf:
f.write(new_stub+"\n")
defmain() ->None:
print("STARTING RUN: Will attempt to fix new syntax in the stubs directory...\n\n")
forpathinchain(Path("stubs").rglob("*.pyi"), Path("stdlib").rglob("*.pyi")):
if"@python2"notinpath.partsand ("protobuf"notinpath.partsor"_pb2"notinstr(path)):
print(f"Attempting to convert {path} to new syntax.")
fix_bad_syntax(path)
print("\n\nSTARTING ISORT...\n\n")
subprocess.run([sys.executable, "-m", "isort", "."])
print("\n\nSTARTING BLACK...\n\n")
subprocess.run([sys.executable, "-m", "black", "."])
print('\n\nRunning "check_new_syntax.py"...\n\n')
subprocess.run([sys.executable, "tests/check_new_syntax.py"])
print("\n\nRunning flake8...\n\n")
subprocess.run([sys.executable, "-m", "flake8", "stdlib stubs"])
if__name__=="__main__":
main()

The second and third commit were done manually.

Closes#6189

[srittau]

Thanks, one thing I noticed below.

[srittau]

This does not re-export, according to PEP 484. (Existing type checkers might still re-export due to __all__, but that is undefined behavior.)

[AlexWaygood]

Interesting, I think we're a little inconsistent about that at the moment, e.g. in our stubs for _collections_abc. Anyhow, I've made the change!

[github-actions]

Diff from mypy_primer, showing the effect of this PR on open source code:

sphinx (https://github.com/sphinx-doc/sphinx)
+ sphinx/util/typing.py: note: In function "_restify_py36":+ sphinx/util/typing.py:267:26: error: Module has no attribute "GenericMeta"; maybe "Generic"? [attr-defined]+ sphinx/util/typing.py: note: In function "_stringify_py36":+ sphinx/util/typing.py:505:33: error: Module has no attribute "GenericMeta"; maybe "Generic"? [attr-defined]+ sphinx/util/typing.py: note: At top level:+ sphinx/util/typing.py:507: error: Unused "type: ignore" comment+ sphinx/util/typing.py:508: error: Unused "type: ignore" comment+ sphinx/util/typing.py:509: error: Unused "type: ignore" comment+ sphinx/util/typing.py:510: error: Unused "type: ignore" comment+ sphinx/util/typing.py:513: error: Unused "type: ignore" comment+ sphinx/util/typing.py:514: error: Unused "type: ignore" comment