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pathlib module

Only one class is exported: pathlib.Path. It always represents a virtual POSIX path inside the sandbox (/mnt/data/foo.txt), never a Windows path even when the host is Windows. PurePath, PurePosixPath, PureWindowsPath, PosixPath, WindowsPath are not separately exposed; the printed repr of a Path is PosixPath(...) for compatibility.

Because the class object and its instances share one type, the class object answers to the instance name: pathlib.Path.__name__ and repr(pathlib.Path) give PosixPath / <class 'PosixPath'>, and pathlib.Path.nonexistent raises type object 'PosixPath' has no attribute 'nonexistent', where CPython names Path (the instance-level spellings, e.g. Path('/a') / 1, match CPython).

Construction

Path(*segments) works. Each segment may be a str or another Path. Bytes paths are rejected with TypeError.

Path.cwd(), on the class or any instance, returns the sandbox’s virtual working directory without a host round-trip; the host sets it per feed and relative paths are resolved against it before any I/O method reaches the host (see os.md). Path.home() is not implemented: the sandbox has no home directory.

Pure (no I/O) methods and attributes

Implemented: name, parent, stem, suffix, suffixes, parts, is_absolute(), joinpath(*other), with_name(name), with_stem(stem), with_suffix(suffix), as_posix(), __fspath__().

The / operator works in both directions (Path("a") / "b", Path("a") / Path("b"), "a" / Path("b")).

Not implemented: anchor, drive, root, relative_to, is_reserved, match, full_match, with_segments.

I/O methods (yield to host)

These yield an OsCall for the host to resolve:

  • exists(), is_file(), is_dir(), is_symlink()
  • read_text(), read_bytes()
  • write_text(data), write_bytes(data), append_text(data), append_bytes(data)
  • mkdir(mode=0o777, parents=False, exist_ok=False), unlink(), rmdir()
  • iterdir(), stat(), rename(target)
  • resolve(), absolute()
  • open(...) — see open.md for the supported file API and divergences

Path.mkdir() parses mode, parents, and exist_ok, but mode is accepted only for signature compatibility: Monty does not model POSIX permission bits. The missing_ok and target_is_directory keyword arguments accepted by other CPython methods are not parsed; pass only the positional arguments documented above.

Path.mkdir()’s too-many-positional error counts only the visible parameters (Path.mkdir() takes from 0 to 3 positional arguments but 4 were given); CPython counts the bound self as well (takes from 1 to 4 … but 5 were given).

Not implemented: glob, rglob, touch, chmod, lchmod, owner, group, symlink_to, hardlink_to, link_to, readlink, lstat, samefile, walk, replace, expanduser.

Path normalization and the sandbox

I/O calls are handled by mounts or a custom os callback. Mounts resolve paths strictly within mounted roots. See filesystem.md.

iterdir() preserves the receiver’s spelling: Path('.').iterdir() returns relative paths such as Path('file.txt'), while Path('subdir').iterdir() returns paths beneath subdir, matching CPython. The host receives an absolute request; the interpreter joins each returned entry’s name onto the original directory path.