optional package gnuplotpy-1.8.spkg causes test failure on sage-4.7.2

[sagetrac-mariah]

sage-4.7.2 with the optional package gnuplotpy-1.8.spkg installed causes the following test failure:

% ./sage -t -long -force_lib "devel/sage/sage/tests/startup.py"
sage -t -long -force_lib "devel/sage/sage/tests/startup.py" 
**********************************************************************
File "/home/mariah/sage/sage-4.7.2-x86_64-Linux-core2-fc-optional/devel/sage/sage/tests/startup.py", line 13:
    sage: sage0("'numpy' in sys.modules")
Expected:
    False
Got:
    True
**********************************************************************
1 items had failures:
   1 of   5 in __main__.example_0
***Test Failed*** 1 failures.
For whitespace errors, see the file /home/mariah/.sage//tmp/startup_30568.py
         [8.0 s]
 
----------------------------------------------------------------------
The following tests failed:


        sage -t -long -force_lib "devel/sage/sage/tests/startup.py"
Total time for all tests: 8.1 seconds
%

Component: interfaces

Keywords: sd40.5

Author: Mike Hansen

Reviewer: Douglas McNeil, Karl-Dieter Crisman

Merged: sage-5.1.beta6

Issue created by migration from https://trac.sagemath.org/ticket/12009

[mwhansen]

Author: Mike Hansen

[sagetrac-dsm]

comment:2

Works for me: applies cleanly against 5.1.beta0 and passes the tests afterwards.

[kcrisman]

comment:3

Mike,

This looks like the right fix, efficient as always, and Doug tested it. Should we at this point make the attribute a single-underscore one instead of double-underscore?

[mwhansen]

Attachment: trac_12009.patch.gz

[mwhansen]

comment:4

I just went ahead and made the double underscore into a single one. Positive review?

[mwhansen]

Changed keywords from none to sd40.5

[kcrisman]

comment:5

Great!

[kcrisman]

Reviewer: Douglas S. McNeil, Karl-Dieter Crisman

[jdemeyer]

Merged: sage-5.1.beta6

[jdemeyer]

Changed reviewer from Douglas S. McNeil, Karl-Dieter Crisman to Douglas McNeil, Karl-Dieter Crisman