rpds-py 2026.5.1

Python bindings to Rust's persistent data structures (rpds)

Python bindings to the Rust rpds crate for persistent data structures.

What’s here is quite minimal (in transparency, it was written initially to support replacing pyrsistent in the referencing library). If you see something missing (which is very likely), a PR is definitely welcome to add it.

Installation

The distribution on PyPI is named rpds.py (equivalently rpds-py), and thus can be installed via e.g.:

$ pip install rpds-py

Note that if you install rpds-py from source, you will need a Rust toolchain installed, as it is a build-time dependency. An example of how to do so in a Dockerfile can be found here.

If you believe you are on a common platform which should have wheels built (i.e. and not need to compile from source), feel free to file an issue or pull request modifying the GitHub action used here to build wheels via maturin.

Usage

Methods in general are named similarly to their rpds counterparts (rather than pyrsistent‘s conventions, though probably a full drop-in pyrsistent-compatible wrapper module is a good addition at some point).

>>> from rpds import HashTrieMap, HashTrieSet, List

>>> m = HashTrieMap({"foo": "bar", "baz": "quux"})
>>> m.insert("spam", 37) == HashTrieMap({"foo": "bar", "baz": "quux", "spam": 37})
True
>>> m.remove("foo") == HashTrieMap({"baz": "quux"})
True

>>> s = HashTrieSet({"foo", "bar", "baz", "quux"})
>>> s.insert("spam") == HashTrieSet({"foo", "bar", "baz", "quux", "spam"})
True
>>> s.remove("foo") == HashTrieSet({"bar", "baz", "quux"})
True

>>> L = List([1, 3, 5])
>>> L.push_front(-1) == List([-1, 1, 3, 5])
True
>>> L.rest == List([3, 5])
True