fix: partial write error handling

[NguyenHoangSon96]

Closes #

Proposed Changes

The current exception classes hierarchy are InfluxDBError -> InfluxDBPartialWriteError and ApiException

• In InfluxDBError there is an important function _get_message(self, response) , this function will run everytime a subclass of InfluxDBError is initialized, inside this function there is a quite heavy function will run, that is _parse_partial_write_line_error_info(data), so when a partial write error occurs _get_message(self, response) will be called at least twice.
  Some issues:
• With the current implementation it is quite hard to make exception classes run efficiently when a partial writes error occurs.
• Exception class should not have any logic that can affect other exceptions. Exception classes should just some simple data carrier objects with very limited functionality as mine knowledge, or at least this is what I have seen on other v3 clients.
• json.loads(response.data) was called multiple times like in Java v3.
• The assumption that every subclass of InfluxDBError will have the same way of parsing the error messages like we do in _get_message(self, response) function is not correct... I think.
  We can try to make everything work more efficiently as possible with the current exception classes implementation, but I still feel It very wrong on the architecture and design perspective.

What I'm trying to do right now is moving all logic inside exception classes to WriteApi class (or wherever than inside exception classes) and making them as lightweight as possible. They should only carry information about the errors;

Checklist

• CHANGELOG.md updated
• Rebased/mergeable
• A test has been added if appropriate
• Tests pass
• Commit messages are conventional
• Sign CLA (if not already signed)

[Copilot]

Pull request overview

This PR refactors write error handling to better distinguish partial-write errors from generic write failures by parsing JSON error bodies and conditionally raising InfluxDBPartialWriteError only when accept_partial is enabled and the response matches the expected “rejected rows” list format.

Changes:

• Update write exception translation to parse JSON bodies and format per-line rejection details for partial writes.
• Adjust sync REST client response decoding to normalize empty bodies to None.
• Expand and update tests to cover partial-write detection, message formatting, and fallback behaviors.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
tests/test_write_api.py	Adds broader unit coverage for write-error classification and fallback messaging; updates existing error-translation tests.
tests/test_influxdb_client_3_integration.py	Loosens assertion on v3 error message content and narrows the tested accept_partial configuration.
influxdb_client_3/write_client/client/write_api.py	Implements new JSON parsing and partial-write detection/formatting in _translate_write_exception.
influxdb_client_3/write_client/_sync/rest_client.py	Avoids decoding empty bodies and normalizes empty data to None.
influxdb_client_3/exceptions/exceptions.py	Changes exception message handling and updates partial-write error types/constructors.

Suppressed comments (1)

influxdb_client_3/exceptions/exceptions.py:69

• These PEP 604 union annotations (int | None, etc.) will fail to parse on Python <3.10. Use Optional[...] (with Optional imported from typing) to preserve compatibility.

class InfluxDBPartialWriteLineError:
    line_number: int | None
    error_message: str | None
    original_line: str | None

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[Copilot]

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Suppressed comments (2)

influxdb_client_3/exceptions/exceptions.py:5

• Python 3.9 is still in the CI matrix, but this module now uses PEP 604 union syntax elsewhere (int | None), so you’ll need Optional available for 3.9-compatible type annotations.

from typing import List

influxdb_client_3/exceptions/exceptions.py:69

• int | None / str | None type syntax is a Python 3.10+ feature and will raise a SyntaxError on Python 3.9 (which is still in .github/workflows/pylint.yml). Use Optional[...] instead for compatibility.

class InfluxDBPartialWriteLineError:
    line_number: int | None
    error_message: str | None
    original_line: str | None

[codecov]

Codecov Report

❌ Patch coverage is 96.99248% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 87.65%. Comparing base (900bc72) to head (26f4fe0).

Files with missing lines	Patch %	Lines
influxdb_client_3/write_client/write_exceptions.py	96.55%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #239      +/-   ##
==========================================
+ Coverage   86.34%   87.65%   +1.31%     
==========================================
  Files          28       28              
  Lines        2072     2042      -30     
==========================================
+ Hits         1789     1790       +1     
+ Misses        283      252      -31     

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[bednar]

I found five issues that need to be addressed before approval.

Review is up to @karel-rehor

[NguyenHoangSon96]

@karel-rehor
This PR is now ready to be reviewed.
Please check when you have time.

[karel-rehor]

I have some concerns about missed opportunities to improve and simplify the API. This is of course open for discussion.

[karel-rehor]

This probably should have been caught in PR140, but to be fully self descriptive and to be more in line with other client APIs, since this error is only used with writes, perhaps it should be name InfluxDBWriteError or InfluxDBServerError or InfluxdDBRestCallError.

[karel-rehor]

Agree with Copilot. Need a fallback message when argument is None.

[karel-rehor]

Seeing that we now have InfluxDBError added in the file exceptions.py can we refactor some technical debt here?

I would perhaps consider the following.

1. move write_exceptions to the exceptions directory.
2. remove ApiException and merge it with what is currently InfluxDBError, which works more like InfluxDBWriteError (see code comment, and other PR comment).
   • Consider that the API at this stage is getting needlessly complex. For an API exception we now have an inheritance chain of ApiException -> InfluxDBError -> InfluxDB3ClientError -> Exception
   • I see that we want to try and preserve Jay Clifford's work, but a lot of this is a direct transposition from Influxdb2 and this PR is an opportunity to further simplify the API as much as possible.
3. Move any exception or error classes related to the write API into write_exceptions.py.
4. ensure naming of all exception classes and files within the API uses consistently either <Tokens>Exception or <Tokens>Error but not both.
5. Some global functions here might make more sense as static class methods, but this requires futher reflection.

[karel-rehor]

If ApiException were to be refactored to simplify inheritence a Union might not be required here and if python OOP works like other languages, I would expect any class inheriting from InfluxDBError could be returned.