tahoe-lafs/trac-2024-07-25

u"py3 not supported" idiom will break in Python 3.3 #1775

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opened 2012-06-20 23:16:24 +00:00 by davidsarah · 1 comment

davidsarah commented

2012-06-20 23:16:24 +00:00

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u"Tahoe-LAFS does not run under Python 3. Please use a version of Python between 2.5 and 2.7.x inclusive."

This will break in Python 3.3 due to PEP 414, which adds the u"..." string syntax.

source:setup.py and source:bin/tahoe-script.template currently use the following idiom near the top of each file to prevent them from producing even-more-confusing-than-necessary syntax errors when run in a Python 3.x interpreter: ``` u"Tahoe-LAFS does not run under Python 3. Please use a version of Python between 2.5 and 2.7.x inclusive." ``` This will break in Python 3.3 due to [PEP 414](http://www.python.org/dev/peps/pep-0414/), which adds the `u"..."` string syntax.

tahoe-lafs added the

labels 2012-06-20 23:16:24 +00:00

tahoe-lafs added this to the 1.10.0 milestone 2012-06-20 23:16:24 +00:00

davidsarah commented

2013-03-15 04:53:06 +00:00

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Fixed in edfb40e5 and 3bdd744b.

Both of these files now have the line:

import sys; assert sys.version_info < (3,), ur"Tahoe-LAFS does not run under Python 3. Please use a version of Python between 2.5 and 2.7.x inclusive."

near the start.

If this is a syntax error (which it is on Python 3.0-3.3 inclusive due to the ur"..."), then the resulting error will include the desired message.

Otherwise, provided there are no other Python 3 syntax errors (which there are not, due to the other changes in these patches), this code will still fail and print the message due to the assertion. That would happen if some future Python version added ur"...", for example.

Fixed in [edfb40e5](https://github.com/tahoe-lafs/tahoe-lafs/commit/edfb40e57c30fcac2d85be3f298d5c1f080322dd) and [3bdd744b](https://github.com/tahoe-lafs/tahoe-lafs/commit/3bdd744b8e39b657b8de468b2163eec84d87a134). Both of these files now have the line: ``` import sys; assert sys.version_info < (3,), ur"Tahoe-LAFS does not run under Python 3. Please use a version of Python between 2.5 and 2.7.x inclusive." ``` near the start. If this is a syntax error (which it is on Python 3.0-3.3 inclusive due to the `ur"..."`), then the resulting error will include the desired message. Otherwise, provided there are no other Python 3 syntax errors (which there are not, due to the other changes in these patches), this code will still fail and print the message due to the assertion. That would happen if some future Python version added `ur"..."`, for example.

tahoe-lafs added the

fixed

label 2013-03-15 04:53:06 +00:00

davidsarah closed this issue

2013-03-15 04:53:06 +00:00