PythonCharmers/python-future

past.translation: support `raise x, y, z`

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#318 opened on Jan 8, 2018

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 (0 comments) (0 reactions) (0 assignees)Python (1,172 stars) (327 forks)batch import
0.20enhancementexceptionshelp wanted

Description

hi! first off, thanks for future and past.translation. they're awesome.

i noticed that autotranslate doesn't support the old raise x, y, z syntax. here's an issue to track adding it, if you want. thanks in advance!

steps to reproduce:

$ echo 'raise None, None, None' > x.py
$ python3
...
>>> from past import autotranslate
>>> autotranslate(['x'])
>>> import x
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<frozen importlib._bootstrap>", line 971, in _find_and_load
  File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 656, in _load_unlocked
  File "<frozen importlib._bootstrap>", line 626, in _load_backward_compatible
  File ".../local3/lib/python3.6/site-packages/past/translation/__init__.py", line 402, in load_module
    code = compile(source, self.pathname, 'exec')
  File ".../3.6/lib/python3.6/lib2to3/fixes/fix_zip.py", line 1
    raise None, None, None
              ^
SyntaxError: invalid syntax
>>>

Contributor guide

Tech stack
python
Domain
developer experience
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
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
Pythonlib2to3
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70
Research direction
Review the translation code in `past/translation/ init .py`, specifically around line 402 where the compilation occurs. Look for how other Python 2 syntaxes are handled (e.g., print statement) and add support for `raise x, y, z`. Consider using lib2to3's fixers or adding a custom transform. Ensure the new syntax is properly translated to Python 3's `raise ... from ...` or multiple exception arguments.