virtual_glob 0.1.1

Globbing of virtual file systems.

virtual-glob

Globbing of remote/virtual file systems.

Motivation

Globbing is a common operation in many programs, but it is not always required to use the local file system, as is the case for glob.glob or pathlib.Path.glob. This package provides a way to glob over remote/virtual file systems.

Apart from python-glob2, which is unmaintained, I could not find another Python packages that provided this functionality, so I made my own!

Usage

Install the package:

pip install virtual-glob

Use the glob function, which can take a pathlib.Path instance, the provided InMemoryPath class, or any other class that implements the VirtualPath below:

from virtual_glob import glob, InMemoryPath

fs = InMemoryPath.from_list(["a/b/c/my1.txt", "e/f/g/my2.txt", "x/y/z/other.txt"])
matches = {p.path for p in glob(fs, "**/my[0-9].txt")}
assert matches == {"a/b/c/my1.txt", "e/f/g/my2.txt"}

See the tests for more examples.

Virtual file systems

The file system must be accessible via a single class, directly mimicking pathlib.Path, with the following protocol:

class VirtualPath(Protocol):
    @property
    def name(self) -> str:
        """Return the name of this path."""

    def is_dir(self) -> bool:
        """Return True if this path is a directory."""

    def iterdir(self: PathType) -> Iterable[PathType]:
        """Iterate over the contents of this directory."""

    def joinpath(self: PathType, *parts: str) -> PathType:
        """Join this path with the given parts."""

    def exists(self) -> bool:
        """Return True if this path exists."""

Rules

• Patterns must be in POSIX format, i.e. / is the path separator.
• Patterns must be relative, i.e. they must not start with /.
• Patterns are case-sensitive.
• Patterns with a trailing / only match directories.
• ** matches zero or more directories, it must be the only thing in a path segment.
• * matches zero or more characters, except /.
• ? matches exactly one character, except /.
• [...] matches one character in the set, except /.
• [!...] matches one character not in the set, except /.

Design

Make as few calls to the underlying file system as possible, particularly for iterdir. For example, looking to "short-circuit" when a pattern contains no "magic" characters.