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Use str.translate to improve performance of normalize_name#254

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hugovk:speedup-canonicalize_name
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Use str.translate to improve performance of normalize_name#254
hugovk wants to merge 2 commits intopypa:masterfrom
hugovk:speedup-canonicalize_name

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@hugovk hugovk commented Jan 10, 2026

We can apply @henryiii's improvement to packaging in pypa/packaging#1030 (see also https://iscinumpy.dev/post/packaging-faster/) to improve the performance of normalize_name and make it ~3.4 times faster.

Benchmark

Run normalize_name(n) on every name in PyPI:

# benchmark_names_distlib.py
import sqlite3
import timeit
from distlib.util import normalize_name

# Get data with:
# curl -L https://github.com/pypi-data/pypi-json-data/releases/download/latest/pypi-data.sqlite.gz | gzip -d > pypi-data.sqlite
# Or ues pre-cached files from:
# https://gist.github.com/hugovk/efdbee0620cc64df7b405b52cf0b6e42

CACHE_FILE = "/tmp/bench/names.txt"
DB_FILE = "/tmp/bench/pypi-data.sqlite"

try:
    with open(CACHE_FILE) as f:
        TEST_ALL_NAMES = [line.rstrip("\n") for line in f]
except FileNotFoundError:
    TEST_ALL_NAMES = []
    with sqlite3.connect(DB_FILE) as conn:
        with open(CACHE_FILE, "w") as cache:
            for (name,) in conn.execute("SELECT name FROM projects"):
                if name:
                    TEST_ALL_NAMES.append(name)
                    cache.write(name + "\n")


def bench():
    for n in TEST_ALL_NAMES:
        normalize_name(n)


if __name__ == "__main__":
    print(f"Loaded {len(TEST_ALL_NAMES):,} names")
    t = timeit.timeit("bench()", globals=globals(), number=1)
    print(f"Time: {t:.4f} seconds")

Benchmark data can be found at https://gist.github.com/hugovk/efdbee0620cc64df7b405b52cf0b6e42

Before

With Python 3.14 on macOS:

❯ python benchmark_names_distlib.py
Loaded 8,344,947 names
Time: 4.6224 seconds

After

❯ python benchmark_names_distlib.py
Loaded 8,344,947 names
Time: 1.3598 seconds

3.4 times faster.

hugovk and others added 2 commits January 10, 2026 16:21
@hugovk
Allow testing feature branches
ae113ac
@hugovk @henryiii
Use translate to improve performance of normalize_name
43ae2ea 
Co-Authored-By: Henry Schreiner <henryschreineriii@gmail.com>
@hugovk
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hugovk commented Jan 19, 2026 •
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Following on from pypa/packaging#1064, this is slower with 3.12 and 3.13, so marking as draft for now.

Testing on Python 3.8 to 3.14 on macOS (python.org versions) using hyperfine:

Python master (s) PR (s) Result
3.8 7.699 ± 0.620 4.620 ± 0.040 PR 1.67x faster
3.9 7.463 ± 0.480 4.775 ± 0.131 PR 1.56x faster
3.10 6.042 ± 0.019 3.947 ± 0.213 PR 1.53x faster
3.11 5.437 ± 0.144 3.598 ± 0.144 PR 1.51x faster
3.12 5.707 ± 0.358 6.907 ± 0.059 ⚠️ master 1.21x faster
3.13 5.248 ± 0.067 6.479 ± 0.163 ⚠️ master 1.23x faster
3.14 5.784 ± 0.605 2.391 ± 0.061 PR 2.42x faster
Details 
❯ hyperfine --warmup 1 -r 3 \
    -n master --prepare 'git checkout master' 'python3.8 benchmark_names_distlib.py' \
    -n PR --prepare 'git checkout speedup-canonicalize_name -q' 'python3.8 benchmark_names_distlib.py'
Benchmark 1: master
  Time (mean ± σ):      7.699 s ±  0.620 s    [User: 6.703 s, System: 0.455 s]
  Range (min … max):    7.054 s …  8.290 s    3 runs

Benchmark 2: PR
  Time (mean ± σ):      4.620 s ±  0.040 s    [User: 4.381 s, System: 0.199 s]
  Range (min … max):    4.574 s …  4.650 s    3 runs

Summary
  PR ran
    1.67 ± 0.14 times faster than master

distlib on  speedup-canonicalize_name [?] via 🐍 v3.14.2 via 💎 v3.1.3 took 49s
❯ hyperfine --warmup 1 -r 3 \
    -n master --prepare 'git checkout master' 'python3.9 benchmark_names_distlib.py' \
    -n PR --prepare 'git checkout speedup-canonicalize_name -q' 'python3.9 benchmark_names_distlib.py'
Benchmark 1: master
  Time (mean ± σ):      7.463 s ±  0.480 s    [User: 6.627 s, System: 0.416 s]
  Range (min … max):    7.111 s …  8.009 s    3 runs

Benchmark 2: PR
  Time (mean ± σ):      4.775 s ±  0.131 s    [User: 4.379 s, System: 0.296 s]
  Range (min … max):    4.679 s …  4.924 s    3 runs

Summary
  PR ran
    1.56 ± 0.11 times faster than master

distlib on  speedup-canonicalize_name [?] via 🐍 v3.14.2 via 💎 v3.1.3 took 50s

❯ hyperfine --warmup 1 -r 3 \
    -n master --prepare 'git checkout master' 'python3.10 benchmark_names_distlib.py' \
    -n PR --prepare 'git checkout speedup-canonicalize_name -q' 'python3.10 benchmark_names_distlib.py'
Benchmark 1: master
  Time (mean ± σ):      6.042 s ±  0.019 s    [User: 5.561 s, System: 0.329 s]
  Range (min … max):    6.021 s …  6.054 s    3 runs

Benchmark 2: PR
  Time (mean ± σ):      3.947 s ±  0.213 s    [User: 3.503 s, System: 0.311 s]
  Range (min … max):    3.751 s …  4.174 s    3 runs

Summary
  PR ran
    1.53 ± 0.08 times faster than master

distlib on  speedup-canonicalize_name [?] via 🐍 v3.14.2 via 💎 v3.1.3 took 41s
❯ hyperfine --warmup 1 -r 3 \
    -n master --prepare 'git checkout master' 'python3.11 benchmark_names_distlib.py' \
    -n PR --prepare 'git checkout speedup-canonicalize_name -q' 'python3.11 benchmark_names_distlib.py'
Benchmark 1: master
  Time (mean ± σ):      5.437 s ±  0.144 s    [User: 4.972 s, System: 0.274 s]
  Range (min … max):    5.279 s …  5.563 s    3 runs

Benchmark 2: PR
  Time (mean ± σ):      3.598 s ±  0.144 s    [User: 3.198 s, System: 0.265 s]
  Range (min … max):    3.463 s …  3.750 s    3 runs

Summary
  PR ran
    1.51 ± 0.07 times faster than master

distlib on  speedup-canonicalize_name [?] via 🐍 v3.14.2 via 💎 v3.1.3 took 43s
❯ hyperfine --warmup 1 -r 3 \
    -n master --prepare 'git checkout master' 'python3.12 benchmark_names_distlib.py' \
    -n PR --prepare 'git checkout speedup-canonicalize_name -q' 'python3.12 benchmark_names_distlib.py'
Benchmark 1: master
  Time (mean ± σ):      5.707 s ±  0.358 s    [User: 5.005 s, System: 0.369 s]
  Range (min … max):    5.439 s …  6.113 s    3 runs

Benchmark 2: PR
  Time (mean ± σ):      6.907 s ±  0.059 s    [User: 6.439 s, System: 0.331 s]
  Range (min … max):    6.846 s …  6.963 s    3 runs

Summary
  master ran
    1.21 ± 0.08 times faster than PR

distlib on  speedup-canonicalize_name [?] via 🐍 v3.14.2 via 💎 v3.1.3 took 48s
❯ hyperfine --warmup 1 -r 3 \
    -n master --prepare 'git checkout master' 'python3.13 benchmark_names_distlib.py' \
    -n PR --prepare 'git checkout speedup-canonicalize_name -q' 'python3.13 benchmark_names_distlib.py'
Benchmark 1: master
  Time (mean ± σ):      5.248 s ±  0.067 s    [User: 4.906 s, System: 0.226 s]
  Range (min … max):    5.183 s …  5.316 s    3 runs

Benchmark 2: PR
  Time (mean ± σ):      6.479 s ±  0.163 s    [User: 6.002 s, System: 0.315 s]
  Range (min … max):    6.328 s …  6.652 s    3 runs

Summary
  master ran
    1.23 ± 0.03 times faster than PR

distlib on  speedup-canonicalize_name [?] via 🐍 v3.14.2 via 💎 v3.1.3 took 31s
❯ hyperfine --warmup 1 -r 3 \
    -n master --prepare 'git checkout master' 'python3.14 benchmark_names_distlib.py' \
    -n PR --prepare 'git checkout speedup-canonicalize_name -q' 'python3.14 benchmark_names_distlib.py'
Benchmark 1: master
  Time (mean ± σ):      5.784 s ±  0.605 s    [User: 5.174 s, System: 0.275 s]
  Range (min … max):    5.370 s …  6.478 s    3 runs

Benchmark 2: PR
  Time (mean ± σ):      2.391 s ±  0.061 s    [User: 2.067 s, System: 0.223 s]
  Range (min … max):    2.321 s …  2.431 s    3 runs

Summary
  PR ran
    2.42 ± 0.26 times faster than master

@hugovk hugovk marked this pull request as draft January 19, 2026 18:34
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