quill-sort 7.4.0

Adaptive sorting that auto-dispatches to the fastest available backend (compiled, GPU, parallel) with a guaranteed numpy/Timsort fallback; Quill.UltraSort engine for billion-element integer workloads.

quill-sort

QuillSort.7 — adaptive sorting that profiles your data at intake and dispatches it to the fastest correct backend available on your machine. When no accelerated backend is installed, or an input is unsupported, it falls back to numpy.sort (or the standard-library Timsort), so a result is never incorrect. At scale it matches or beats those baselines; for tiny inputs the dispatch overhead is a few microseconds, so it is never meaningfully slower.

The compiled CPU backends (parallel radix, samplesort) now ship inside quill-sort's binary wheels, and a self-tuning dispatcher replaces hardcoded crossovers with measured per-machine latency — so pip install quill-sort is fast out of the box, with no separate accelerator packages to install.

import numpy as np
import quill

# List API. quill_sort sorts IN PLACE by default (like list.sort) and returns
# the list; use quill_sorted (or inplace=False) for a non-mutating sorted().
quill.quill_sort([3, 1, 4, 1, 5, 9])               # -> [1, 1, 3, 4, 5, 9]  (mutates input)
quill.quill_sorted(records, key=lambda r: r["age"])  # non-mutating, like sorted()

# Array API — dispatches a numpy buffer to a compiled / GPU / parallel backend.
a = np.random.randint(0, 2**40, 20_000_000)
quill.sort_array(a)                                # sorted ndarray

---

Two APIs: list and array

Quill exposes two entry points. Which one you use determines the magnitude of the speedup.

API	Input / output	Throughput (numeric, reference machine)	Reason
quill_sort(list)	list in, list out	comparable to numpy.sort; ~2–3x faster than sorted() / list.sort() on numeric data	The call wraps a fast kernel in np.asarray(...) and .tolist(). Those two conversions dominate total runtime, so most of the kernel's advantage is amortized away (Amdahl's law).
sort_array(ndarray)	ndarray in, ndarray out	~2.7–3x (int64), ~2x (float64) vs numpy.sort; higher with inplace=True	No conversions: the raw buffer is handed directly to the fastest installed backend.

In short: if your data is a Python list, the conversion cost bounds the speedup, and quill_sort performs at roughly numpy.sort throughput while remaining several times faster than the built-in sorted(). To obtain the full multi-threaded or GPU speedup, keep your data in numpy arrays and call sort_array.

All figures below were measured on a reference machine (Windows 11, 28-core CPU, NVIDIA RTX 4060 Ti, numpy 2.4.6) using a freshly shuffled array on every timed run, reflecting cold-sort throughput rather than warm or already-sorted inputs. Results vary with CPU, GPU, array size, and dtype.

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Installation

pip install quill-sort              # core + bundled compiled CPU backends (see below)
pip install quill-sort[fast]        # + numpy + psutil (accurate RAM sensing)
pip install quill-sort[polars]      # + polars (extra no-compile parallel sort)
pip install quill-sort[gpu]         # + cupy   (NVIDIA GPU sort)
pip install quill-sort[all]         # numpy + pandas + psutil + polars

The compiled CPU backends — parallel MSD radix, parallel samplesort, and the single-threaded radix — are bundled inside quill-sort's per-platform binary wheels (quill._native), so a plain pip install quill-sort gets the fast path with nothing else to install. Where no binary wheel matches your platform, the source build recompiles them if a C++17 compiler is present, and if that fails Quill falls through to polars/numpy/Timsort — installation never fails for lack of a toolchain.

To detect your hardware and install the appropriate accelerators interactively, run the setup wizard after installing:

quill setup

The wizard reports which backends are available, offers to install any that are missing, and calibrates the parallel and GPU thresholds for your machine.

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Backend selection

sort_array() profiles the array and evaluates a priority chain, selecting the first backend that is installed and supports the input. Each step has a measured crossover (min_n) below which it is not used, and any backend error falls back to numpy.sort.

sort_array(ndarray)
        |
        v
  eligible?  (1-D, dtype kind i/u/f, itemsize <= 8, value-only, C-contiguous)
        | no  -------------------------------------------------> numpy.sort
        | yes
        v
  dense bounded int64/uint64?  --> counting sort (np.bincount)   single-thread
        | no
        v
  first available + supporting backend, in priority order:
        rust_voracious   (compiled radix, n >= 1M)
        cupy_gpu         (GPU, n >= 2M, fits in free VRAM)
        polars           (multi-threaded sort, n >= 200k)
        numpy_parallel   (integer partition sort, n >= 5M)
        |
        | any error / nothing eligible
        v
  numpy.sort   (the baseline; always correct, never slower than numpy)

NaN values are removed before any backend runs and re-appended at the end (numpy convention), so a backend that cannot order NaN never receives one. Descending order is applied as a post-sort reverse. quill.available_backends() reports the backends your machine will use, in priority order.

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Backends

Backend	How to enable	Measured (int64 vs numpy.sort)	Notes
ips4o	bundled (quill._native)	~3x (int/float)	Parallel comparison samplesort. Top CPU tier at large n.
rust_parallel_radix	bundled (quill._native)	~2.7–3x (float64 ~2x)	Parallel MSD radix across a thread pool.
rust_voracious	bundled (quill._native)	~2.7–3x (float64 ~2x)	Parallel radix (i64/f64).
simd_companion	bundled (quill._native)	~1.4x	Single-threaded radix; SIMD-friendly.
cupy_gpu	pip install quill-sort[gpu]	~4x (float64 ~2.5x)	GPU radix sort via CuPy. Accounts for the host-to-device-to-host transfer and still wins for large arrays that fit in VRAM.
polars	pip install quill-sort[polars]	~2.3x (float64 ~1.7x)	Delegates to the polars multi-threaded sort. No compiler required.
numpy_parallel	pip install quill-sort[fast]	~1.1x (integers only)	Thread-parallel np.partition sample sort. A small, reliable integer-only gain; uses few workers because the benefit saturates at memory bandwidth.
counting sort	pip install quill-sort[fast]	~1.7–2.8x	np.bincount for dense bounded int64/uint64. O(n + k), single-threaded.
numpy.sort	included with numpy	1.0x (baseline)	The fallback. Used on any error or ineligible dtype.

Without numpy, Quill still sorts correctly via the standard-library Timsort. Correctness has no required dependencies.

---

Array API: sort_array()

import numpy as np
import quill

a = np.random.randint(0, 2**40, 20_000_000)

s = quill.sort_array(a)                    # sorted copy; a is unchanged
quill.sort_array(a, inplace=True)          # sort a in place; returns a
d = quill.sort_array(a, descending=True)   # reverse order

quill.available_backends()
# -> ['rust_voracious', 'cupy_gpu', 'polars', 'numpy_parallel']

sort_array matches numpy.sort exactly — including negatives, mixed int/float promotion, and NaN-to-end ordering. At scale it beats numpy.sort (see above); small arrays (below ~200k) go straight to numpy.sort, so it is never meaningfully slower. For sub-millisecond sorts the Python call overhead is a few microseconds — negligible in absolute terms, but it means the ratio can dip below 1.0 on tiny inputs.

Top-k: quill_topk()

To retrieve only the k smallest or largest elements, quill_topk uses numpy's argpartition (introselect, O(n)) rather than a full O(n log n) sort:

quill.quill_topk(scores, 10)                 # 10 smallest, ascending
quill.quill_topk(scores, 10, largest=True)   # 10 largest, descending
quill.quill_topk(rows, 5, key=lambda r: r.size)

Accepts a list or an ndarray and returns a list. On the reference machine, for k=10 over a 5M numeric array, it is ~4x faster than np.sort(arr)[:k] (it avoids the full sort) and many times faster than sorted(data)[:k].

analyze()

quill.analyze([3, 1, 4, 1, 5, 9])
# {'n': 6, 'dtype': 'int_pos', 'presorted': False, 'dense': True, ...}

---

List API: quill_sort() / quill_sorted()

Routes numeric lists through the fast numeric kernel and all other data through Timsort. Because it returns a list, it incurs the conversion cost described above and performs at approximately numpy.sort throughput.

Mutation: quill_sort defaults to inplace=True — it sorts the list in place and returns it, like list.sort() (which means b = quill_sort(a) also sorts a). Use quill_sorted(...) — or quill_sort(..., inplace=False) — for the non-mutating behavior of the built-in sorted().

quill.quill_sort([3, 1, 4, 1, 5, 9])              # in place; returns the list
quill.quill_sort(data, key=lambda x: x["score"])  # objects via a key
quill.quill_sort(data, reverse=True)              # descending
quill.quill_sort(data, inplace=False)             # return a new list
quill.quill_sort(data, parallel=True)             # force multi-core
quill.quill_sort(data, stable=False)              # unstable, faster on numeric
result = quill.quill_sorted(iterable)             # non-mutating, mirrors sorted()

Full signature:

quill.quill_sort(
    data,                        # list, generator, range, ndarray, Series, DataFrame
    key=None,                    # sort key function (as in sorted())
    reverse=False,               # descending order
    inplace=True,                # mutate in place (False returns a new list)
    parallel=False,              # use multiple cores (automatic on large numeric data)
    high_performance_mode=False, # skip the prompt on the external-sort path
    silent=False,                # suppress status output
    stable=True,                 # True matches sorted() exactly; False is faster
    stats=False,                 # return (sorted_list, stats_dict)
)

The stable parameter

stable=True (the default) guarantees that equal elements retain their original relative order, identical to Python's sorted(). stable=False permits faster unstable kernels on numeric data when ordering among equal elements is irrelevant.

The stats parameter

result, stats = quill.quill_sort(data, stats=True)
# stats = {'time_ms': 12.3, 'n': 1000000}

---

Fallback guarantee

Every accelerated path is wrapped so that any failure — a missing backend, a GPU out-of-memory condition, a native panic, or an unsupported dtype — falls back to numpy.sort, or to the standard-library Timsort when numpy is absent. The Rust extension is built with panic = "unwind", so a native panic becomes a catchable Python exception rather than terminating the process. A result is therefore never incorrect, and on substantial inputs never slower than the numpy baseline (on tiny sub-millisecond sorts the dispatch overhead is a few microseconds).

# Surface backend errors instead of falling back silently:
QUILL_BACKEND_DEBUG=1 python your_script.py

---

Correctness contract

Quill's output matches sorted() and numpy.sort on every supported input.

None values sort to the end (to the start with reverse=True):

quill.quill_sort([3, None, 1, None, 2])
# -> [1, 2, 3, None, None]

NaN values in float data sort to the end (to the start with reverse=True), matching numpy:

quill.quill_sort([3.0, float("nan"), 1.0, 2.0])
# -> [1.0, 2.0, 3.0, nan]

Mixed int/float lists are promoted to float64 and use the fast float path:

quill.quill_sort([1, 2.5, 3, 4.0])
# -> [1, 2.5, 3, 4.0]

Negative integers are handled natively via two's-complement radix, and keyed sorts are stable by default.

---

Supported types

• int, float, str, bytes — native fast paths
• Mixed int + float — promoted to float64
• Negative integers — handled natively
• None values — sorted to the end (to the start with reverse=True)
• float('nan') — sorted to the end (to the start with reverse=True)
• numpy.ndarray — sorted via the backend chain (use sort_array for the full speedup)
• pandas.Series — sorted and returned as a new Series
• pandas.DataFrame — sorted by column(s) via key='column_name'
• Any generator or iterator — materialized to a list, sorted, returned

---

Plugin system

A plugin teaches Quill to sort a custom type. It declares the types it handles and a prepare() that converts instances into something Quill sorts natively, with an optional postprocess to reconstruct the objects.

from quill import register_plugin, QuillPlugin

class MyPlugin(QuillPlugin):
    handles = (MyCustomClass,)
    name    = "my_custom_class"

    @staticmethod
    def prepare(data, key, reverse):
        items       = [x.value for x in data]
        postprocess = lambda sorted_vals: [MyCustomClass(v) for v in sorted_vals]
        return items, key, postprocess

register_plugin(MyPlugin)
quill.quill_sort(list_of_my_objects)

Built-in plugins cover numpy.ndarray, pandas.Series, pandas.DataFrame, range, and generators/iterators. Custom backends (not just type plugins) can be registered with quill._backends.register_backend(...).

---

Command-line interface

quill                 # benchmark demo across data types
quill setup           # detect backends, offer to install accelerators, calibrate
quill visualize       # animated illustration of a sort
python -m quill ...    # equivalent without the installed console script

quill setup writes its calibrated thresholds to ~/.quill/config.json.

---

Performance tuning

• Install the appropriate accelerator: quill-fastsort for the compiled radix backend, [polars] for a no-compiler multi-threaded sort, or [gpu] for an NVIDIA card. quill setup recommends and installs these interactively.
• Use sort_array on numpy arrays to avoid the list conversion cost.
• Pass stable=False on the list path for additional speed on numeric data when stable ordering is not required.
• Run quill setup to calibrate the parallel and GPU crossovers for your hardware.
• Install psutil for accurate available-RAM sensing; without it, Quill assumes 2 GB.

---

Troubleshooting

• quill_sort(list) performs at numpy.sort throughput, not the array-API speedup, because the asarray/tolist round trip dominates. For the full speedup, keep data in numpy arrays and call sort_array.
• If sort_array is not using an accelerated backend, check quill.available_backends(). The backend may not be installed, the array may be below the backend's crossover, or its dtype/itemsize may be ineligible. Set QUILL_BACKEND_DEBUG=1 to report the reason rather than falling back silently.
• The GPU backend engages only when the array fits in free VRAM with headroom; otherwise it falls back to the CPU radix or numpy.sort.
• If equal elements are reordered, use stable=True (the default).
• If the external sort triggers unexpectedly, install psutil for accurate RAM sensing, or pass high_performance_mode=True to skip the prompt.

---

Development

pip install -e ".[all,dev]"
pytest                          # full suite
pytest -m slow                  # parallel / large-data tests

# Build the compiled Rust backend locally (optional):
cd rustext && maturin develop --release

The compiled Rust backend (the rustext crate) is published separately as quill-fastsort: stable-ABI binary wheels for Windows, manylinux x86_64/aarch64, and macOS x86_64/arm64, plus a source distribution.

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Requirements

• Python 3.8+
• numpy — optional but recommended (pip install quill-sort[fast])
• quill-fastsort — optional compiled radix backend
• psutil — optional, for accurate RAM sensing
• polars — optional backend (pip install quill-sort[polars])
• cupy — optional GPU backend (pip install quill-sort[gpu], NVIDIA only)
• pandas — optional, for Series/DataFrame support

A C or Rust toolchain is not required to install; accelerated backends are distributed as prebuilt wheels.

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License

MIT — Isaiah Tucker