Use lowercase type everywhere

[AlexWaygood]

This PR was prepared using the following script:

import ast
import re
import subprocess
import sys
from itertools import chain
from pathlib import Path
from typing import NamedTuple


class DeleteableImport(NamedTuple):
    old: str
    replacement: str


FAILURES = []


def fix_bad_syntax(path: Path) -> None:
    with open(path) as f:
        stub = f.read()

    lines = stub.splitlines()
    tree = ast.parse(stub)
    imports_to_delete = {}
    type_from_typing = False

    class BadImportFinder(ast.NodeVisitor):
        def visit_ImportFrom(self, node: ast.ImportFrom) -> None:
            nonlocal type_from_typing

            if node.module != "typing":
                return

            if any(cls.name == "Type" for cls in node.names):
                type_from_typing = True
            else:
                return

            new_import_list = [cls for cls in node.names if cls.name != "Type"]

            ### DEALING WITH EXISTING IMPORT STATEMENTS ###

            # Scenario (1): Now we don't need *any* imports from typing any more.
            # Don't touch the imports in collections/__init__.pyi as it causes a mypy crash (don't know why)
            if not new_import_list and path != Path("stdlib/collections/__init__.pyi"):
                imports_to_delete[node.lineno - 1] = DeleteableImport(old=ast.unparse(node), replacement="")

            # Scenario (2): we still need imports from typing; the existing import statement is only one line
            elif node.lineno == node.end_lineno:
                imports_to_delete[node.lineno - 1] = DeleteableImport(
                    old=ast.unparse(node),
                    replacement=ast.unparse(ast.ImportFrom(module="typing", names=new_import_list, level=0)),
                )

            # Scenario (3): we still need imports from typing; the existing import statement is multiline.
            else:
                for cls in node.names:
                    if cls.name == "Type":
                        imports_to_delete[cls.lineno - 1] = DeleteableImport(
                            old=f"Type," if cls.asname is None else f"Type as {cls.asname},", replacement=""
                        )

    BadImportFinder().visit(tree)

    if not type_from_typing:
        return

    for lineno, (old_syntax, new_syntax) in imports_to_delete.items():
        lines[lineno] = lines[lineno].replace(old_syntax, new_syntax)

    try:
        new_tree = ast.parse("\n".join(lines))
    except SyntaxError:
        sys.stderr.write(f"Error converting new syntax in {path}")
        FAILURES.append(path)
    else:
        lines_with_bad_syntax = []

        class OldSyntaxFinder(ast.NodeVisitor):
            def visit_Subscript(self, node: ast.Subscript) -> None:
                if isinstance(node.value, ast.Name) and node.value.id == "Type":
                    lines_with_bad_syntax.append(node.lineno - 1)
                self.generic_visit(node)

        OldSyntaxFinder().visit(new_tree)

        for lineno in lines_with_bad_syntax:
            lines[lineno] = re.sub(fr"(\W)Type\[", fr"\1type[", lines[lineno])

    with open(path, "w") as f:
        f.write("\n".join(lines) + "\n")


def main() -> None:
    print("STARTING RUN: Will attempt to fix new syntax in typeshed directory...\n\n")
    for path in chain(Path("stdlib").rglob("*.pyi"), Path("stubs").rglob("*.pyi")):
        if "@python2" in path.parts:
            print(f"Skipping {path}: Python-2 stub")
        elif Path("stubs/protobuf/google/protobuf") in path.parents:
            print(f"Skipping {path}: protobuf stub")
        else:
            print(f"Attempting to convert {path} to new syntax.")
            fix_bad_syntax(path)

    print("\n\nSTARTING ISORT...\n\n")
    for folder in {"stdlib", "stubs", "tests"}:
        subprocess.run([sys.executable, "-m", "isort", folder])

    print("\n\nSTARTING BLACK...\n\n")
    subprocess.run([sys.executable, "-m", "black", "."])

    if FAILURES:
        print("\n\nFAILED to convert the following files to new syntax:\n")
        for path in FAILURES:
            print(f"- {path}")
    else:
        print("\n\nThere were ZERO failures in converting to new syntax. HOORAY!!\n\n")

    print('\n\nRunning "check_new_syntax.py"...\n\n')
    subprocess.run([sys.executable, "tests/check_new_syntax.py"])

    print('\n\nRunning "stubtest_stdlib.py"...\n\n')
    subprocess.run([sys.executable, "tests/stubtest_stdlib.py"])


if __name__ == "__main__":
    main()

[AlexWaygood]

I think the third-party stubtest failures for requests are unrelated to this PR?

[AlexWaygood]

The only change to requests stubs that this PR makes is in stubs/requests/requests/models.pyi, and that looks fine to me.

[hauntsaninja]

Looks like it's failing on master too, https://github.com/python/typeshed/actions/runs/1669875816
requests 2.27.1 was released in the last two days, so maybe that's it

[srittau]

#6858 for part 1 for a requests fix.

[srittau]

I did a spot check and this looks good.

[github-actions]

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉

[AlexWaygood]

Thanks for the mypy fix @sobolevn 😀

[sobolevn]

Happy to help! 😉