problem with import / namespace

[Laszlo Nagy]

ohad frand wrote:
> Hi
> I have a problem that the solution to it must be very simple but i 
> couldnt fint it's answer in the internet so far (i searched for couple 
> of days)
> the problme is as follows:
>
> i have two directories e.g. "\\1" and "\\2"
> in each directory i have two files with the same names e.g. "tmp1.py" 
> and "tmp2.py"

So this is what you have:

/1/tmp1.py
/1/tmp2.py
/2/tmp1.py
/2/tmp2.py

> each tmp2.py file imports tmp1 from its same directory (import tmp1) - 
> thats the problem
> if i execute one file (\\1\tmp2.py) than the execution is ok
> but when i try after that to execute the second file (\\2\tmp2.py) 
> than the tmp1 file from the wrong directory ( - directory 1 in this 
> case) is imported instead.

When you try to import a module, python starts to search for it. The was 
it does the search is very well defined. It mostly depends on the 
current directory and sys.path. You can read more about this here:

http://docs.python.org/tut/node8.html#searchPath

This is very basic thing - you should read and go through the tutorial 
before asking questions like this. :-)

> i tried many things to try to solve it, i removed the previous path 
> from sys.path and added the new one, i tried to change current working 
> directory with os.chdir()
> I tried to delete from locals and from globals the name tmp1 before 
> running the second file but nothing worked.
> please help
The problem is still not well defined. Python works as expected and 
documented, but apparently you do not know how to import 1/tmp2.py from 
2/tmp1.py.  There are several ways to do it, and we cannot tell which 
one is correct. It depends on what are these modules for.

Here are the solution that you would use (most likely) as a beginner:


#1 first, rename your "1" and "2" directories to "one" and "two". If you 
are creating a package with modules, then you have to define the 
package's name with its directory. Since identifiers cannot begin with 
digits in Python, you need to use an identifier-like name for your 
subdirs. It is a good idea anyway. A package name called "1" would tell 
nothing about what it does?
#2 place your main application in /app/app.py
#3 create /app/one/__init__.py and /app/two/__init__.py files (they can 
be empty)
- inside your app.py file either make sure that the current dir is /app, 
or insert /app in the first place in sys.path


Then for example, inside two/tmp1.py you can do this:


import one.tmp1
import one.tmp2
import two.tmp1

one.tmp1.somefunc()
two.tmp1.somefunc()


You got the idea.

    Laszlo