[GRASS-dev] [GRASS GIS] #3790: Cleanup gettext usage for python code

[GRASS GIS]

#3790: Cleanup gettext usage for python code
--------------------------+-------------------------
  Reporter:  pmav99       |      Owner:  grass-dev@…
      Type:  enhancement  |     Status:  closed
  Priority:  normal       |  Milestone:  7.8.0
 Component:  Python       |    Version:  svn-trunk
Resolution:  fixed        |   Keywords:
       CPU:  Unspecified  |   Platform:  Unspecified
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Comment (by wenzeslaus):

 The things in lib/python are potentially (and actually) used as Python
 modules by other applications or scripts. Thus from
 https://pymotw.com/2/gettext/index.html#module-localization, it is
 actually the second option which applies:

 > //For a library, or individual module, modifying `__builtins__` is not a
 good idea because you don’t know what conflicts you might introduce with
 an application global value. You can import or re-bind the names of
 translation functions by hand at the top of your module.//

 The doctests and interative command line are probably where the issues
 will happen first. See Django practices from
 https://docs.djangoproject.com/en/dev/topics/i18n/translation/ as linked
 in #1739:

 > //Python’s standard library gettext module installs _() into the global
 namespace, as an alias for gettext(). In Django, we have chosen not to
 follow this practice, for a couple of reasons: //
 >    //Sometimes, you should use gettext_lazy() as the default translation
 method for a particular file. Without _() in the global namespace, the
 developer has to think about which is the most appropriate translation
 function.//

 >    //The underscore character (_) is used to represent “the previous
 result” in Python’s interactive shell and doctest tests. Installing a
 global _() function causes interference. Explicitly importing gettext() as
 _() avoids this problem.//

 To run doctests, use

 {{{
 python -m doctest -v example.py
 }}}

 or (often already included in code):

 {{{
 if __name__ == "__main__":
     import doctest
     doctest.testmod()
 }}}

 both taken from https://docs.python.org/2/library/doctest.html, so the
 question is if you have an particular issue. Another things to test are
 Python in command line, Python console in GUI, and Jupyter Notebook. (But
 the doctest are where the issues definitively emerged in the past.)

 Please note that I never understood all the details of #1739 as noted
 there, so maybe we have things to investigate more. Also, try to examine
 `do_doctest_gettext_workaround()` which doctests need when the builin is
 modified or perhaps even in other cases.

 Finally, is there any overhead in centralizing the tr string installation?
 So far we were relatively successful in keeping the GUI separate (whether
 for performance or code organization reasons).

-- 
Ticket URL: <https://trac.osgeo.org/grass/ticket/3790#comment:4>
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