PythonCharmers/python-future

libfuturize.fixes.fix_absolute_import duplicates initial comments

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#281 opened on Apr 27, 2017

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 (1 comment) (0 reactions) (0 assignees)Python (1,172 stars) (327 forks)batch import
0.19bughelp wanted

Description

precondition

  • Create thing/{__init__.py,foo.py,bar.py}
  • Fill foo.py with the following: 
    #!/usr/bin/env python
# -*- encoding: utf-8 -*-
import bar
  • run fix_absolute_import on thing

expected

foo.py should have become:

#!/usr/bin/env python
# -*- encoding: utf-8 -*-
from __future__ import absolute_import
from . import bar

observed

foo.py has actually become:

#!/usr/bin/env python
# -*- encoding: utf-8 -*-
from __future__ import absolute_import
#!/usr/bin/env python
# -*- encoding: utf-8 -*-
from . import bar

Contributor guide

Tech stack
python
Domain
toolingdeveloper experience
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Python basicsUnderstanding of libfuturize
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70
Research direction
The bug is in the `fix absolute import` fixer within `libfuturize.fixes`. The issue is that when processing a file with initial comments, the fixer duplicates those comments after inserting the `from future import absolute import` line. Look at the logic that handles the initial comment block and the insertion point for the future import. The expected behavior is to insert the future import without duplicating the comments. Investigate the relevant file (likely `libfuturize/fixes/fix absolute import.py`) and the method that inserts imports, possibly by checking if comments are being re added unnecessarily. The fix might involve ensuring that the comment block is only written once. The issue is clear from the provided example, and no maintainer input is required.