piwheels

Back in 2021 I did some analysis of PyPI package names and version strings in the post The rinds of the Cheese Shop menu. Five years on, let's see how things have changed.

At the time of writing, PyPI contains:

• 736,344 packages with at least one version (up from 311,063 in 2021 — nearly 2.4×)
• 8,234,245 versions (up from 2,766,603 — nearly 3×)

The index has grown dramatically. Let's dig in.

Longest package names

The most common length of package name is still 8 characters — the same as in 2021 (like gpiozero).

The least common lengths are 77, 79, 80, 83, 91, 92, 99, 113, 114, 122, and 188 — each occurring exactly once.

The longest package names have changed quite a bit since 2021. The new list reads more like a stream of consciousness than a software registry:

• zzz...zzz (188)
• program-to-get-any-string-as-user-input-and-output-code-for-the-string-reverse-the-string-and-code-using-alphabet-position (122)
• red-does-not-support-this-version-of-python-please-follow-one-of-the-install-guides-at-docs-discord-red (103) — a package that exists solely to tell you it doesn't support your Python version

Shortest package names

At the other end of the scale, there are 24 single-character packages. There are 706 two-character packages, and 7,685 three-character ones.

Package name separators

PyPI canonicalises package names, normalising hyphens, underscores, and dots all to hyphens. So the only separator that appears in a canonicalised name is the hyphen.

Of the 736,344 packages, 53.7% (395,184) contain at least one hyphen, while 46.3% (341,160) have no separator at all.

Starting characters

The most common starting character is p (12.5%), thanks to the dominance of py- and python- prefixed packages. The least common is 9 with just 16 packages.

Looking at the first two characters, the top five are py, od, dj, co, and re. od (for odoo) has pushed its way into second place since 2021, when it didn't feature at all.

Looking at the first three characters, odo has overtaken dja into second place behind pyt:

Common prefixes

What are the most popular hyphenated prefixes?

django- remains by far the most common prefix with 16,046 packages. But the most striking story is odoo: counting odoo- and all its versioned variants (odoo14-, odoo13-, odoo12-, odoo11-, odoo10-, odoo9-, odoo8-) together gives over 20,000 packages with an odoo prefix.

New entrants since 2021 reflecting the AI ecosystem boom:

Common suffixes

Flipping the analysis around, the most common suffixes tell a story about how packages are categorised by purpose:

-client (6,898), -sdk (6,315), and -cli (6,099) top the list. -mcp sits in fifth place with 4,730 packages — another sign of the AI era — while -ai (1,721) and -agent (1,089) are also well represented.

Most common words in package names

Splitting package names on hyphens, underscores, and dots, the most common individual words are:

addon (18,357) edges out django (17,464) at the top — most addon packages are Odoo addons. mcp (13,420) is in third place, ahead of python (12,648). ai (3,914) and agent (2,391) make strong showings that wouldn't have featured in 2021.

Benford's Law

Benford's Law states that in many naturally occurring collections of numbers, the leading digit is likely to be small. Testing this against version numbers, the pattern holds in 2026 much as it did in 2021 — the first non-zero digit of version numbers broadly follows the expected distribution, with the fit becoming closer still when looking at all digits:

As in 2021, 1 is slightly over-represented and 9 slightly over-represented compared to expectation.

Number of versions per package

Over a quarter of packages (29.3%, or 216,019) have only a single version.

The package with the most versions is spanishconjugator with a remarkable 9,475 versions, more than three times the 2021 record holder (pulumi, with 2,566).

Version length

• The most common version length is 5, matching the 1.2.3 format — same as 2021
• The most common version string is still 0.1.0, now occurring 195,112 times (up from 57,258 in 2021)
• There are 666,778 distinct version strings (up from 233,734)

The longest version belongs to elvisgogo at 138 characters:

99999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999111111111111111111111111111111111100000000.6.0

lyricsprocessor retains its 84-character 0.1.404040... version in second place, still going strong five years later.

Version schemes

77.2% of all versions use the canonical three-part 1.2.3 scheme:

Over half of all versions — 52.3% — still carry major version 0, indicating the package is considered pre-stable by its author.

Pre-release versions

More than one in eight versions (12.7%, or 1,044,068) carry a pre-release tag. dev is the most common:

Non-numeric versions

• There are 68 packages with entirely non-numeric versions (down from 166 in 2021, suggesting PyPI has cleaned up many old oddities)
• Only one package has more than one non-numeric version: dstufft-testpkg, still proudly offering versions dog and watwatwat after all these years
• The longest non-numeric version is still jw-util's -class.-jw.util.version.Version- (32 chars) — an accidental repr() of a Version class that has somehow survived since 2014

King's English

Using the system dictionaries, how many package names are real words?

• 17,271 packages appear in the US English dictionary (up from 11,131)
• 17,108 packages appear in the British English dictionary (up from 11,031)
• 53 packages appear only in the British dictionary (up from 39)

New British-only arrivals since 2021 include calibre, candour, equaliser, gaol, kerb, manoeuvre, maths, rigour, sceptic, serialise, visualise, and waggon.

Claude

This blog post was (in part) an experiment to see if I could get Claude to generate an updated version of the 2021 blog post from new data. The post was manually reviewed and edited before being published. See the repo for further info: github.com/piwheels/stats-2026