module reimported if imported from different path

Question

In a big application I am working, several people import same modules differently e.g. import x or from y import x the side effects of that is x is imported twice and may in

Answer 1

I can only replicate this if main.py is the file you are actually running. In that case you will get the current directory of main.py on the sys path. But you apparently also have a system path set so that mypackage can be imported.

Python will in that situation not realize that mymodule and mypackage.mymodule is the same module, and you get this effect. This change illustrates this:

def add(x):
    from mypackage import mymodule
    print "mypackage.mymodule path", mymodule
    mymodule.l.append(x)
    print "updated list",mymodule.l

def get():
    import mymodule
    print "mymodule path", mymodule
    return mymodule.l

add(1)
print "lets check",get()

add(1)
print "lets check again",get()


$ export PYTHONPATH=.
$ python  mypackage/main.py 

mypackage.mymodule path 
mymodule path 

But add another mainfile, in the currect directory:

realmain.py:
from mypackage import main

and the result is different:

mypackage.mymodule path 
mymodule path 

So I suspect that you have your main python file within the package. And in that case the solution is to not do that. :-)