Double import in grok

Question

This is a normal case of mutual import. Suppose you have the following layout

./test.py
./one
./one/__init__.py
./one/two
./one/two/__init__.py
./one/two/m.py
./one/two/three
./one/two/three/__init__.py
./one/two/three/four
./one/two/three/four/__init__.py
./one/two/three/four/e.py
./one/two/u.py

And you have

test.py

 from one.two.three.four import e

one/two/three/four/e.py

from one.two import m

one/two/m.py

print "m"
import u

one/two/u.py

print "u"
import m

When you run the test.py program, you expect, of course:

python test.py
m
u

Which is the expected behavior. Modules have already been imported, and they are only once. In Grok, this does not happen. Suppose to have the following app.py

import os; import sys; sys.path.insert(1,os.path.dirname( os.path.realpath( __file__ ) ))
import grok
from one.two.three.four import e

class Sample(grok.Application, grok.Container):
    pass

what you obtain when you run paster is:

$ bin/paster serve parts/etc/deploy.ini
2009-10-07 15:26:57,154 WARNING [root] Developer mode is enabled: this is a security risk and should NOT be enabled on production servers. Developer mode can be turned off in etc/zope.conf
m
u
m
u

What's going on in here ?

from a pdb stack trace, both cases are imported by martian:

    /Users/sbo/.buildout/eggs/martian-0.11-py2.4.egg/martian/core.py(204)grok_package()  
  -> grok_module(module_info, grokker, **kw)                                             
    /Users/sbo/.buildout/eggs/martian-0.11-py2.4.egg/martian/core.py(209)grok_module()   
  -> grokker.grok(module_info.dotted_name, module_info.getModule(),                      
    /Users/sbo/.buildout/eggs/martian-0.11-py2.4.egg/martian/scan.py(118)getModule()     
  -> self._module = resolve(self.dotted_name)                                            
    /Users/sbo/.buildout/eggs/martian-0.11-py2.4.egg/martian/scan.py(191)resolve()       
  -> __import__(used)                                                                    

The only difference between the first case and the second one is that the first shows the progressive import of e and then of m. In the second case it directly imports m.

Thanks for the help

Answer 1

This could possibly be a side-effect of the introspection Grok does, I'm not sure.

Try to put a pdb.set_trace() in m, and check at the stack trace to see what is importing the modules.