Python client for the L database: a pure-Rust IPC core (TCP framing, wire serialization, LZ4 decompression) exposed through PyO3.

Install a wheel from the v0.1.0 release (pip install <wheel>), or build from source with uv run maturin develop.

import l

conn = l.connect("localhost", 5001)
conn.query("t:([]sym:`A`B`A;price:1.5 2.5 3.5)")
print(conn.query("select from t").to_python())
# {'sym': ['A', 'B', 'A'], 'price': [1.5, 2.5, 3.5]}
conn.close()

Connection is also a context manager; connect(host, port, "user:pass") authenticates. Queries return K values — call .to_python() to convert. Pass arguments built with the K constructors: conn.query_with_args("{x+y}", l.K.int(10), l.K.int(32)).

Null numerics arrive as sentinels (0N = -2**31, 0Nj = -2**63, float nulls = nan). Server errors raise RuntimeError; the connection stays usable afterwards. Blocking I/O releases the GIL; the contract is one connection per thread — a second thread using the same connection gets a clean "Already borrowed" error, never a corrupted stream.

l -p 5001 &
L_TEST_PORT=5001 L_BIN=path/to/l uv run pytest   # Rust: cargo test -p l-rs

~200 tests against a live server: the full atom/vector type matrix in both directions, structures (nested lists, dicts, keyed/wide/empty tables, enum columns), null sentinels and infinities of every type, unicode/NUL/10M-element boundaries, the server error taxonomy, LZ4 wire compression, and kill-the-server robustness. L_BIN enables the sacrificial-server tests; L_STRESS=1 adds 100MB-scale runs.