Update Python on Mac: 60 of Top 100 Packages Refuse 3.9.6

The Python on a Mac is version 3.9.6. On this Mac mini, running macOS 26.4.1 with Command Line Tools 26.5, /usr/bin/python3 --version prints Python 3.9.6, and it comes with pip 21.2.4. The Python 3.9 release schedule (PEP 596) dates 3.9.6 to June 28, 2021. The 3.9 branch kept going until 3.9.25 and reached end of life on October 31, 2025, so the copy on a Mac is 19 patch releases behind a branch that is itself finished. /usr/bin/python3 is a 118,928-byte stub that passes the call to the Command Line Tools copy. Apple ships it the way it ships Ruby and Perl: the macOS Catalina release notes describe these runtimes as "included in macOS for compatibility with legacy software."

Earlier today I measured the same problem with Ruby. In update Ruby on Mac, the system Ruby 2.6.10 refused 10 of 12 popular gems with loud errors. I expected Python to fail the same way. It didn't. It installed everything I asked for and exited 0, which turned out to be the bigger problem.

12 packages, 12 exit codes of 0, 12 old versions

I installed 12 packages people commonly reach for, each into its own empty directory with /usr/bin/python3 -m pip install --target, so nothing touched the system. Every install exited 0. The logs held 0 lines containing "warning" or "error". Then I checked which version pip had actually picked:

Package	Installed on 3.9.6	Latest on PyPI	Latest requires	Releases skipped
requests	2.32.5	2.34.2	>=3.10	5
numpy	2.0.2	2.5.4	>=3.12	28
pandas	2.3.3	3.0.6	>=3.11	6
fastapi	0.128.8	0.143.0	>=3.10	49
openai	2.48.0	3.28.0	>=3.10	44
pillow	11.3.0	12.3.0	>=3.10	5
pydantic	2.13.5	2.14.0	>=3.10	1
boto3	1.42.97	1.43.111	>=3.10	112
pytest	8.4.2	9.1.1	>=3.10	6
scipy	1.13.1	1.18.1	>=3.12	14
click	8.1.8	8.5.0	>=3.10	10
sqlalchemy	2.0.54	2.1.4	>=3.11	5

None of the 12 got its current release. pip reads each release's Requires-Python field, quietly drops the ones that exclude 3.9.6, and installs the newest one left. That is how pip is designed to work, and it is the right call for old interpreters, but it means a plain pip install never tells you that you're behind. numpy 2.0.2 is from August 2024. openai 2.48.0 is a whole major version behind, so the current docs and examples may not match the library you got. The installs took between 0 and 12 seconds each and looked completely normal.

The first visible complaint came later, when the code ran. Importing the requests I'd just installed printed this before making a successful request:

NotOpenSSLWarning: urllib3 v2 only supports OpenSSL 1.1.1+, currently the 'ssl'
module is compiled with 'LibreSSL 2.8.3'. See: https://github.com/urllib3/urllib3/issues/3020

The system Python's ssl module is built against LibreSSL 2.8.3, older than the LibreSSL 3.3.6 that /usr/bin/openssl uses on the same Mac. The urllib3 issue the warning links to explains why v2 stopped supporting it.

Pinning the latest version gives a misleading error

If a requirements file pins a current release, the install does fail, but the message doesn't mention Python at all:

$ /usr/bin/python3 -m pip install requests==2.34.2
ERROR: Could not find a version that satisfies the requirement requests==2.34.2
  (from versions: 0.2.0, 0.2.1, ... 2.32.4, 2.32.5)
ERROR: No matching distribution found for requests==2.34.2

The version list stops at 2.32.5 because pip has already removed everything that needs 3.10. A reader who doesn't know that would reasonably decide 2.34.2 doesn't exist, or that PyPI is having a problem. Exit code 1. pip 21.2.4 can't help either: it doesn't know the --dry-run flag, which arrived in later pip versions, so you can't preview what it would pick.

How much of PyPI refuses Python 3.9.6

Twelve packages is a sample I chose. To get a number that isn't, I took the top 100 PyPI packages by downloads (the list updated October 1, 2026), pulled each one's metadata from the PyPI JSON API, and checked every non-yanked, non-prerelease version's requires_python against 3.9.6.

• 60 of the top 100 have a latest release that refuses 3.9.6. In the top 10 it's 4: boto3, botocore, urllib3 and requests. In the top 25 it's 14, and in the top 50 it's 30.
• 51 of the 60 require 3.10 or later, 7 require 3.11 (pandas, sqlalchemy, pyarrow, websockets, platformdirs, rpds-py, soupsieve), and 2 require 3.12 (numpy, scipy).
• Added up, a 3.9.6 user is 749 releases behind across those 60 packages. boto3 and botocore account for 112 each, because they release almost every weekday.
• pip itself is on the list. Its latest, 26.2.1, needs 3.10, so upgrading the pip that ships with the system Python stops at 26.0.1.

Most of this is recent. Only 4 packages broke with 3.9 before October 2025: scipy in June 2024, numpy in August 2024, then click and markdown-it-py in 2025. Seven more dropped it in the weeks before the October 31 end of life, and 49 followed after. If a 3.9.6 setup worked fine a year ago, that's why it may not now.

The 40 that still install their latest release on 3.9.6 are mostly small dependencies with broad support, such as packaging, certifi, idna, six, typing-extensions and pyyaml, plus some larger ones like cryptography, httpx, jinja2, rich, lxml, ruff and beautifulsoup4.

How to update Python on Mac

You don't replace /usr/bin/python3. It belongs to the Command Line Tools, and people who try to delete it end up asking why Python 3.9.6 can't be removed from macOS. You install a newer Python next to it and make sure your shell finds that one first.

With Homebrew, this Mac already had [email protected] (3.14.7). I created a virtual environment with it and installed the same 12 packages:

/opt/homebrew/bin/python3 -m venv ~/venvs/work
~/venvs/work/bin/pip install requests numpy pandas fastapi openai pillow \
  pydantic boto3 pytest scipy click sqlalchemy

That took 22 seconds, and all 12 came out at the latest versions in the table: requests 2.34.2, numpy 2.5.4, pandas 3.0.6, openai 3.28.0 and so on. Two details from that run:

• Use a venv, not a global pip install. Homebrew's Python is marked as externally managed, so pip install outside a venv fails with a different error, covered in externally-managed-environment on Mac. The system 3.9.6 doesn't have that marker, which is one reason it's so easy to use by accident.
• The two pips share one cache. pip 26.2.1 printed WARNING: Cache entry deserialization failed, entry ignored 24 times, because pip 21.2.4 had just written entries to the same ~/Library/Caches/pip in an older format. The warnings are harmless and the install succeeded, but they look alarming the first time.

As of October 11, 2026, brew info python3 resolves the plain python name to [email protected] (3.15.0), which I didn't install for this test. If you'd rather not use Homebrew, the python.org macOS installers put a framework build in /Library/Frameworks and add it to your PATH. The Python on macOS documentation covers both routes. Keeping Homebrew's copy current is covered in brew update vs brew upgrade.

Where Python 3.9.6 still runs after you update

Installing a new Python changes what your interactive shell finds. It doesn't change three other places:

• Scripts with #!/usr/bin/python3. The shebang names the stub directly, so those scripts keep getting 3.9.6 and its old packages.
• launchd jobs. With the default job PATH, env -i PATH=/usr/bin:/bin:/usr/sbin:/sbin python3 -V prints Python 3.9.6 on this Mac, while my SSH shell gets 3.14.7. A job that calls python3 runs the old one unless its plist sets PATH, as covered in launchd plist environment variables.
• python3 -m pip install --user from the old interpreter. Packages land under ~/Library/Python/3.9, where the new Python never looks.

The fix in every case is the same: call the venv's interpreter by full path, like ~/venvs/work/bin/python, in shebangs and plists. The system shell has the same split, as update Bash on Mac showed with Bash 3.2.57.

FAQ

What version of Python comes with macOS?

On macOS 26.4.1 with Command Line Tools 26.5, /usr/bin/python3 is Python 3.9.6 with pip 21.2.4. Python 3.9.6 was released on June 28, 2021, and the 3.9 branch reached end of life on October 31, 2025, so it gets no security fixes. Its ssl module is built against LibreSSL 2.8.3. /usr/bin/python3 is a stub that runs the Command Line Tools copy.

How do I update Python on a Mac?

Install a newer Python alongside the system one, with Homebrew (brew install python) or the python.org macOS installer, then create a virtual environment with it and install packages there. Don't delete or replace /usr/bin/python3, because it belongs to the Command Line Tools. Scripts with #!/usr/bin/python3 and launchd jobs using the default PATH still run 3.9.6, so point them at the new interpreter by its full path.

Why does pip install an old version of a package on my Mac?

If pip is running under the system Python 3.9.6, it skips every release whose Requires-Python excludes 3.9 and installs the newest release that still allows it, without a warning. In a test of 12 popular packages it installed an old version of all 12, for example numpy 2.0.2 instead of 2.5.4. Of the top 100 PyPI packages, 60 have a latest release that needs Python 3.10 or newer. Run python3 -m pip --version to see which Python pip belongs to.

Update, October 11, 2026: git is the one bundled tool Apple has updated recently, and it is still six releases behind. Apple Git-155 is 2.50.1, and it failed 29 of 30 probes taken from the 2.51 to 2.56 release notes, 5 of them silently. The test is in update git on Mac.

Method: on October 11, 2026 I installed 12 packages on a Mac mini M4 (Mac16,10) running macOS 26.4.1 with Command Line Tools 26.5, each into its own empty --target directory, using /usr/bin/python3 3.9.6 and pip 21.2.4, then installed the same 12 into a fresh venv made with Homebrew's [email protected] (3.14.7). The census covers the top 100 entries of hugovk's top-pypi-packages list (updated October 1, 2026), checked against PyPI's JSON API on October 11 using pip's own version-specifier code; a release counts as refusing 3.9.6 when its first non-yanked file's requires_python excludes it, and prereleases are ignored. The scripts and output are in research/update-python-mac-raw (pipprobe.sh, census.py, census.json, brewvenv.txt). I didn't test Intel Macs, pyenv, uv or the python.org installer, and I deleted the /tmp test directories afterward.