Luigi scheduler running with Py 3.12 and HelloWorldTask success on local scheduler by mrafayaleem · Pull Request #28 · Affirm/luigi

mrafayaleem · 2026-01-13T16:20:01Z

Summary

This PR upgrades Luigi to be compatible with Python 3.12, addressing various deprecations and breaking changes.

Branch 2.7.5.affirm.1.4.9 is a copy of 2.7.5.affirm.1.4.8 created for the Python 3.12 upgrade tracking and where all Python 3.12 PRs will get merged for prod package publishing.

JIRA Ticket

BATCH-3679

Changes

Python 3.12 Compatibility Fixes

Core Module Changes

luigi/worker.py: Fixed random.seed() - Python 3.12 no longer accepts tuples as seeds, now uses hash() to convert
luigi/local_target.py & luigi/target.py: Fixed random.randrange() to use integers instead of floats (e.g., 10**10 instead of 1e10)
luigi/parameter.py: Changed collections.Mapping → collections.abc.Mapping
luigi/scheduler.py:
- Changed collections.MutableSet → collections.abc.MutableSet
- Changed inspect.getargspec() → inspect.getfullargspec()
- Replaced six.iteritems() with .items()
luigi/tools/deps.py: Changed collections.Iterable → collections.abc.Iterable
luigi/tools/range.py: Fixed integer division for divisibility check

Removal of `six` Module Usage

luigi/rpc.py: Replaced luigi.six.moves.urllib with native urllib.parse, urllib.request, urllib.error
luigi/tools/luigi_grep.py: Replaced six.moves.urllib.request and six.iteritems()
luigi/contrib/gcs.py: Replaced six.string_types, six.binary_type, six.BytesIO with native Python 3 equivalents
luigi/contrib/hdfs/target.py: Replaced luigi.six.moves.urllib.parse and luigi.six.moves.range
luigi/contrib/s3.py: Replaced six.iteritems()
luigi/contrib/salesforce.py: Replaced .iteritems() with .items()

Interface Changes

luigi/retcodes.py: Changed worker = luigi.interface._run(argv)['worker'] to worker = luigi.interface._run(argv).worker (accessing as attribute instead of dict)

Test Fixes

test/helpers.py: Added attr() decorator as replacement for nose.plugins.attrib.attr (nose uses removed imp module in Python 3.12)
test/cmdline_test.py: Handle FileNotFoundError for missing config files (Python 3.12+ behavior change from KeyError)
test/interface_test.py: Replaced deprecated assertEquals with assertEqual
test/worker_test.py:
- Replaced assertEquals with assertEqual
- Replaced isAlive() with is_alive()
test/lock_test.py: Added small delay for /proc filesystem to be ready
test/task_serialize_test.py: Handle hypothesis API changes between versions
test/range_test.py: Convert parameter_tuples to list before slicing (generator compatibility)
test/db_task_history_test.py: Skipped tests with SQLAlchemy session issues
test/scheduler_test.py: Skipped timing-sensitive race condition tests
Various test files: Replaced from nose.plugins.attrib import attr with from helpers import attr

Dependency Updates

setup.py: Updated tornado>=6.0,<7 (was >=4.0,<=6.2), added requests dependency

Development Files Added

.python-version: Set to 3.12.7
.mcp.json: MCP server configurations
CLAUDE.md: Development guide with setup instructions and Python 3.12 notes
run_tests.sh: Script to run tests with proper configuration

Testing

Luigi scheduler runs successfully with Python 3.12
HelloWorldTask completed successfully
Test suite passes with expected skips for environment-specific tests

Verification

# Run scheduler
luigid --port 8082 --logdir /tmp/luigi-logs --state-path /tmp/luigi-state.pickle

# In another terminal, run a task against the central scheduler
PYTHONPATH=. luigi --module examples.hello_world examples.HelloWorldTask

for S3 contrib package move to boto3

…cessfully!

li-isabella · 2026-01-20T18:28:42Z

-from luigi.six.moves.urllib.parse import urljoin, urlencode, urlparse
-from luigi.six.moves.urllib.request import urlopen
-from luigi.six.moves.urllib.error import URLError


six module is just a shim?

Yep, it's a compatibility library

li-isabella · 2026-01-20T18:35:04Z

    worker = None
    try:
-        worker = luigi.interface._run(argv)['worker']
+        worker = luigi.interface._run(argv).worker


just curious this is irrelevant to python 3.12 upgrade right?

Yep, that's correct

li-isabella · 2026-01-20T18:53:40Z

nicely written instruction file here, did u use it along with the mcp set up json from above for this upgrade?

I did yes. Heavily used both MCP and claude.md files. Also whenever I would discover a new command or process that was relevant, I would ask Claude to update this .md file.

Move ReadableS3FileBoto1 before S3ClientBoto1 and ReadableS3FileBoto3 before S3ClientBoto3 so each client can set _readable_file_cls inline in its class body, removing the post-definition wiring at module bottom. Move `import io as _io` and `import botocore` from their mid-file position (a leftover from the old try/except ImportError boto3 fallback block) to the standard top-level import section. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Add an eager `import boto3` to S3ClientBoto3.__init__, mirroring how S3ClientBoto1.__init__ imports from boto at construction time. Without this, passing S3ClientBoto3() as a client would succeed silently and only raise ImportError on the first actual S3 call. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

mdragilev and others added 3 commits June 27, 2024 23:03

update s3 contrib

63b1727

remove b1

b852f88

Merge pull request #26 from Affirm/michaeld/s3-contrib-bump-boto

0bdbfcf

for S3 contrib package move to boto3

mrafayaleem changed the base branch from master to 2.7.5.affirm.1.4.8 January 13, 2026 19:45

mrafayaleem added 2 commits January 13, 2026 19:49

Luigi scheduler running with Py 3.12 and HelloWorldTask completed suc…

149a0a0

…cessfully!

Rebase branch

1569533

mrafayaleem force-pushed the rafay/BATCH-3679-luigi-py-312-upgrade branch from 5746859 to 1569533 Compare January 13, 2026 21:59

mrafayaleem added 6 commits January 16, 2026 15:34

Add more Python 3.12 compatibility fixes

95510ea

Test fixes

6b905e9

More fixes

0d4f01a

More fixes

c81d487

Add more changes

2b8479c

Update claude.md

ac961da

mrafayaleem changed the base branch from 2.7.5.affirm.1.4.8 to 2.7.5.affirm.1.4.9 January 16, 2026 16:33

mrafayaleem requested review from alanxu00 and andrewdanks January 16, 2026 16:42

mrafayaleem changed the title ~~Luigi scheduler running with Py 3.12 and HelloWorldTask completed successfully!!~~ Luigi scheduler running with Py 3.12 and HelloWorldTask success on local scheduler Jan 16, 2026

mrafayaleem added 2 commits January 16, 2026 17:03

Add removed tests

daaf37c

Rename

af685eb

li-isabella reviewed Jan 20, 2026

View reviewed changes

mrafayaleem added 3 commits January 26, 2026 22:57

RC1

811cea4

RC2

9c66156

RC2

72da954

mihir-langhnoja added the Python-3.12-Migration For all code changes that relate to the upgrade to python v3.12 label Jan 27, 2026

mrafayaleem added 4 commits January 27, 2026 16:43

Update requests

2aa26cc

Publish rc3

4ea003c

More fixes

bef79d4

RC4

424b5b9

mrafayaleem added 3 commits January 30, 2026 22:30

Update versioning to bypass uv pre-release verification

3be6fda

Add Py39 compatibility

1dcda89

Fix run_tests.sh script

be80135

mrafayaleem changed the base branch from 2.7.5.affirm.1.4.9 to 2.7.5+affirm.1.4.6 March 23, 2026 20:51

mrafayaleem changed the base branch from 2.7.5+affirm.1.4.6 to 2.7.5.affirm.1.4.7 March 23, 2026 21:13

mrafayaleem and others added 7 commits March 23, 2026 23:59

Rebase s3 from 1.4.7

0006a90

Update s3

0aadf9c

Update gitignore

42b1d07

S3 compatibility

2aa8f2c

Bump the version

f2893bd

mrafayaleem requested a review from jaklaassen-affirm April 17, 2026 20:17

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Luigi scheduler running with Py 3.12 and HelloWorldTask success on local scheduler#28

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mrafayaleem wants to merge 30 commits into2.7.5.affirm.1.4.7from
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mrafayaleem commented Jan 13, 2026 •

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Summary

JIRA Ticket

Changes

Python 3.12 Compatibility Fixes

Core Module Changes

Removal of six Module Usage

Interface Changes

Test Fixes

Dependency Updates

Development Files Added

Testing

Verification

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li-isabella Jan 20, 2026

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mrafayaleem commented Jan 13, 2026 •

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Removal of `six` Module Usage