Hacktoberfest 2026: the issues maintainers tagged for October, open and beginner-friendly. Browse Hacktoberfest issues

bug: Incorrect serialization of numeric values

Open
#1,113 8 comments 1 reaction 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
35/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
postgresql, python
Domain
databases

Research direction

Start in tests/test_codecs/test_numeric and add 10000 to the cases in test_numeric to reproduce the failure. Trace the numeric serialization logic responsible for returning 1E+4 instead of 10000, then run the test and confirm the existing cases still pass with the expected decimal string preserved.

Written by the indexing model from the issue text.

Description

  • asyncpg version: 0.29.0
  • PostgreSQL version: 13
  • Do you use a PostgreSQL SaaS? If so, which? Can you reproduce
    the issue with a local PostgreSQL install?    : no SaaS, yes reproducable with local postgres
  • Python version: 3.10
  • Platform: linux
  • Do you use pgbouncer?: no
  • Did you install asyncpg with pip?: yes
  • If you built asyncpg locally, which version of Cython did you use?: none
  • Can the issue be reproduced under both asyncio and
    uvloop?    : yes

This happens when query selects a numeric column. Numbers like 10000, 100000, etc. get serialized in scientific notation. For example 10000 becomes 1E+4.

To reproduce the error, you can do the following:

Inside tests/test_codecs/test_numeric if 10000 is added in cases then the test fails, due to incorrect serialization logic.

    async def test_numeric(self):
        # Test that we handle dscale correctly.
        cases = [
            '0.001',
            '0.001000',
            '1',
            '1.00000',
            '10000', # new test case
        ]

fail error:

line 614, in test_numeric
    self.assertEqual(str(res), case)
AssertionError: '1E+4' != '10000'
Dominant language
Python
Stars
8.1k
Forks
469
Avg merge
2d 20h
Merged PRs (30d)
9

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from MagicStack/asyncpg

All issues in MagicStack/asyncpg

Similar issues

More Python issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.