ctools

strange thing ideed...

in the correct case obs[0] is a “proxy”:
<gammalib.cta.GCTAObservation; proxy of <Swig Object of type 'GCTAObservation *' at 0x1020d5690> >

in the bad case, obs[0] is just a pointer:
<Swig Object of type 'GCTAObservation *' at 0x10042cf90>

Still more funny is that cta is always a “proxy”, so strange things happen when cta is appended to obs.

when importing ctools, some gammalib modules are imported, but do not seem to be regularly accessible:

>>> import ctools
>>> import sys
>>> print sys.modules.keys()
['gammalib.sky', 'encodings.codecs', 'sysconfig', 'os.path', 'encodings.encodings', '_mwl', 'ctools.os', 'imp', '_app', 'zipimport', 'encodings.utf_8', 'ctools.imp', '_com', '_support', '_cta', 'signal', 'gammalib.support', 'gammalib.gammalib', 'stat', 'ctools.tools', 'encodings', 'abc', 're', '_fits', 'mpl_toolkits', 'gammalib.linalg', 'UserDict', 'swig_runtime_data4', 'codecs', 'ctools.gammalib', 'paste', 'gammalib.fits', 'gammalib', '_locale', '_lat', 'traceback', 'gammalib.model', 'os', 'gammalib.imp', '_sre', '_test', 'gammalib.opt', '__builtin__', '_sky', 'gammalib.numerics', 'posixpath', 'errno', '_obs', '_vo', 'sre_constants', 'gammalib.mwl', '_warnings', 'gammalib.com', 'encodings.__builtin__', '_codecs', '_numerics', 'gammalib.sys', '_base', '_sysconfigdata', 'gammalib.obs', 'gammalib.vo', 'posix', 'encodings.aliases', 'exceptions', 'sre_parse', 'abrt_exception_handler', 'gammalib.test', 'copy_reg', 'sre_compile', 'gammalib.lat', '_tools', 'ctools.sys', 'site', '__main__', 'ctools', 'linecache', 'gammalib.app', 'gammalib.base', 'gammalib.xspec', '_xml', '_abcoll', 'gammalib.cta', 'genericpath', '_opt', 'warnings', '_linalg', 'sys', 'readline', 'types', '_model', '_weakref', 'gammalib.os', '_weakrefset', 'gammalib.xml', '_xspec']
>>> dir(gammalib)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'gammalib' is not defined
>>> dir(gammalib.gammlib)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'gammalib' is not defined

Overall, I think the root problem is that the user can import the ctools without importing gammalib, ending up with a system in a fishy state.
The simple solution (without trying to fully understand the strange behaviour) is to import gammalib at the top of the ctools __init__.py.

> head -5 $CTOOLS/lib64/python2.7/site-packages/ctools/__init__.py
# import gammalib first
import gammalib

# Import sub modules
from .tools import *

As an additional note, for a reason that I do not understand, with just import ctools, the gammalib module does not become
visible to the user so that the user would not even know that gammalib has been imported before ctools,
and would have to import gammalib anyway to have the module fully available in its script/session.

+1 to do this change now ... if there’s new or remaining issues we’ll notice it throughout the week.

This warning in the user manual should be removed:
https://github.com/ctools/ctools/blame/d58354de28fa603dbb1599f3f5f0e382763548b2/doc/source/user_manual/getting_started/python.rst#L21

Jürgen, do you want to do this change directly or should I make a commit?

for the fun of it, I have created py firt PR...
https://github.com/ctools/ctools/pull/1

woohoo

ok... too much excitement !

https://github.com/bregeon/ctools/tree/fiximport