Re-organize directory structure (#4971)

See discussion in #2491

Co-authored-by: Ivan Levkivskyi <ilevkivskyi@dropbox.com>

stdlib/dbm/__init__.pyi

@@ -0,0 +1,24 @@
+from types import TracebackType
+from typing import Iterator, MutableMapping, Optional, Type, Union
+from typing_extensions import Literal
+
+_KeyType = Union[str, bytes]
+_ValueType = Union[str, bytes]
+
+class _Database(MutableMapping[_KeyType, bytes]):
+    def close(self) -> None: ...
+    def __getitem__(self, key: _KeyType) -> bytes: ...
+    def __setitem__(self, key: _KeyType, value: _ValueType) -> None: ...
+    def __delitem__(self, key: _KeyType) -> None: ...
+    def __iter__(self) -> Iterator[bytes]: ...
+    def __len__(self) -> int: ...
+    def __del__(self) -> None: ...
+    def __enter__(self) -> _Database: ...
+    def __exit__(
+        self, exc_type: Optional[Type[BaseException]], exc_val: Optional[BaseException], exc_tb: Optional[TracebackType]
+    ) -> None: ...
+
+class error(Exception): ...
+
+def whichdb(filename: str) -> str: ...
+def open(file: str, flag: Literal["r", "w", "c", "n"] = ..., mode: int = ...) -> _Database: ...

stdlib/dbm/dumb.pyi

@@ -0,0 +1,25 @@
+from types import TracebackType
+from typing import Iterator, MutableMapping, Optional, Type, Union
+
+_KeyType = Union[str, bytes]
+_ValueType = Union[str, bytes]
+
+error = OSError
+
+class _Database(MutableMapping[_KeyType, bytes]):
+    def __init__(self, filebasename: str, mode: str, flag: str = ...) -> None: ...
+    def sync(self) -> None: ...
+    def iterkeys(self) -> Iterator[bytes]: ...  # undocumented
+    def close(self) -> None: ...
+    def __getitem__(self, key: _KeyType) -> bytes: ...
+    def __setitem__(self, key: _KeyType, value: _ValueType) -> None: ...
+    def __delitem__(self, key: _KeyType) -> None: ...
+    def __iter__(self) -> Iterator[bytes]: ...
+    def __len__(self) -> int: ...
+    def __del__(self) -> None: ...
+    def __enter__(self) -> _Database: ...
+    def __exit__(
+        self, exc_type: Optional[Type[BaseException]], exc_val: Optional[BaseException], exc_tb: Optional[TracebackType]
+    ) -> None: ...
+
+def open(file: str, flag: str = ..., mode: int = ...) -> _Database: ...

stdlib/dbm/gnu.pyi

@@ -0,0 +1,35 @@
+from types import TracebackType
+from typing import List, Optional, Type, TypeVar, Union, overload
+
+_T = TypeVar("_T")
+_KeyType = Union[str, bytes]
+_ValueType = Union[str, bytes]
+
+class error(OSError): ...
+
+# Actual typename gdbm, not exposed by the implementation
+class _gdbm:
+    def firstkey(self) -> Optional[bytes]: ...
+    def nextkey(self, key: _KeyType) -> Optional[bytes]: ...
+    def reorganize(self) -> None: ...
+    def sync(self) -> None: ...
+    def close(self) -> None: ...
+    def __getitem__(self, item: _KeyType) -> bytes: ...
+    def __setitem__(self, key: _KeyType, value: _ValueType) -> None: ...
+    def __delitem__(self, key: _KeyType) -> None: ...
+    def __len__(self) -> int: ...
+    def __enter__(self) -> _gdbm: ...
+    def __exit__(
+        self, exc_type: Optional[Type[BaseException]], exc_val: Optional[BaseException], exc_tb: Optional[TracebackType]
+    ) -> None: ...
+    @overload
+    def get(self, k: _KeyType) -> Optional[bytes]: ...
+    @overload
+    def get(self, k: _KeyType, default: Union[bytes, _T]) -> Union[bytes, _T]: ...
+    def keys(self) -> List[bytes]: ...
+    def setdefault(self, k: _KeyType, default: _ValueType = ...) -> bytes: ...
+    # Don't exist at runtime
+    __new__: None  # type: ignore
+    __init__: None  # type: ignore
+
+def open(__filename: str, __flags: str = ..., __mode: int = ...) -> _gdbm: ...

stdlib/dbm/ndbm.pyi

@@ -0,0 +1,34 @@
+from types import TracebackType
+from typing import List, Optional, Type, TypeVar, Union, overload
+
+_T = TypeVar("_T")
+_KeyType = Union[str, bytes]
+_ValueType = Union[str, bytes]
+
+class error(OSError): ...
+
+library: str = ...
+
+# Actual typename dbm, not exposed by the implementation
+class _dbm:
+    def close(self) -> None: ...
+    def __getitem__(self, item: _KeyType) -> bytes: ...
+    def __setitem__(self, key: _KeyType, value: _ValueType) -> None: ...
+    def __delitem__(self, key: _KeyType) -> None: ...
+    def __len__(self) -> int: ...
+    def __del__(self) -> None: ...
+    def __enter__(self) -> _dbm: ...
+    def __exit__(
+        self, exc_type: Optional[Type[BaseException]], exc_val: Optional[BaseException], exc_tb: Optional[TracebackType]
+    ) -> None: ...
+    @overload
+    def get(self, k: _KeyType) -> Optional[bytes]: ...
+    @overload
+    def get(self, k: _KeyType, default: Union[bytes, _T]) -> Union[bytes, _T]: ...
+    def keys(self) -> List[bytes]: ...
+    def setdefault(self, k: _KeyType, default: _ValueType = ...) -> bytes: ...
+    # Don't exist at runtime
+    __new__: None  # type: ignore
+    __init__: None  # type: ignore
+
+def open(__filename: str, __flags: str = ..., __mode: int = ...) -> _dbm: ...