serpentium 0.0.3

Drop-in performance accelerators for CPython, bundled. floatium + copium + randium.

serpentium

Drop-in performance accelerators for CPython, bundled.

pip install serpentium and several hot paths in the standard library transparently start running on faster native code — no code changes, and no import required: serpentium auto-enables at interpreter startup.

import random
from datetime import datetime
import html

deck = list(range(52))
random.shuffle(deck)                           # ~8x faster, served by Rust (randium)
datetime.strptime("2026-06-07", "%Y-%m-%d")    # faster, fully stdlib-compatible (datetimium)
html.unescape("Tom & Jerry")               # ~4x faster, served by Rust (htmlium)

Serpentium aims for every accelerator to be a true drop-in: same results, down to error messages. CPython's own tests for the modules it touches pass with serpentium installed (python tools/cpython_suite.py).

What's inside

Element	Main target	Backend
randium	the random module — random(), randint/randrange/_randbelow, shuffle	Rust
datetimium	datetime.strptime (locale-independent formats)	Python
htmlium	html.escape, html.unescape (and HTMLParser, which calls unescape)	Rust
floatium	repr(float), str(float), f"{x:.3f}", float(str)	C++ (dep)
copium	copy.deepcopy	dep

randium, datetimium and htmlium ship inside serpentium; floatium and copium are separately-maintained packages pulled in as dependencies.

Benchmarks

CPython 3.14, release build. serpentium wins where a whole Python loop moves to native code (shuffle, deepcopy, entity decoding); per-call primitives merely tie CPython's hand-tuned C (the honest story — see INTERNALS.md).

Operation	stdlib	serpentium	speedup
random.shuffle(list[1000])	158 µs	19 µs	8.3×
copy.deepcopy (pyperformance bm_deepcopy)	7.8 µs	1.3 µs	6.0×
html.unescape (text with entities)	4.3 µs	0.95 µs	4.5×
html.escape (clean paragraph)	208 ns	62 ns	3.3×
datetime.strptime("%Y-%m-%d")	3.77 µs	1.54 µs	2.4×
f"{x:.3f}" (float formatting)	348 ns	160 ns	2.2×
datetime.strptime("%Y-%m-%d %H:%M:%S")	4.67 µs	2.75 µs	1.7×
random.sample(10k, 100)	20.7 µs	17.5 µs	1.2×
random.randint(1, 6)	157 ns	150 ns	1.05×
random.random()	54 ns	51 ns	1.04×
html.unescape (no entities)	42 ns	42 ns	1.0×

Control

Auto-enabled by default. To opt out:

SERPENTIUM_AUTOPATCH=0 python ...     # per-process
python -m serpentium disable          # persistent (writes a marker file)
python -m serpentium status           # show what's active

Or drive it explicitly from code:

import serpentium
serpentium.install(randium=True, datetimium=True, htmlium=True)   # toggle individually
serpentium.uninstall()                                            # restore the stdlib

Documentation

Design, compatibility guarantees, the in-place-patching mechanism, the test strategy, and building from source are in INTERNALS.md.

License

Dual-licensed under either MIT or Apache-2.0, at your option.