import problems in packages

[Stéphane Ninin]

Hello all,


I have an ImportError problem, which is probably correct,
but I do not understand it. And how to fix it...


Here is the basic structure of the code (I have reduced it first).

ROOT:
/main.py
/Handlers/__init__.py (empty)
/Handlers/Handlers.py
/Handlers/HandlerFactory. py
/Handlers/Default/__init__.py (empty)
/Handlers/Default/Handlers.py
/Handlers/Default/HandlerFactory. py

Now, for the content of the files:

ROOT/main.py contains:
def main():
command = 'A'
from Handlers.Handle rFactory import HandlerFactory
handler = HandlerFactory( ).makeHandler(c ommand)

main()


ROOT/Handlers/Handlers.py contains:

class HandlerBase(obj ect):
pass


ROOT/Handlers/HandlerFactory. py contains:

def HandlerFactory( ):
import Handlers.Defaul t.HandlerFactor y
return Handlers.Defaul t.HandlerFactor y.HandlerFactor y()


ROOT/Handlers/Default/Handlers.py contains:

from Handlers.Handle rs import HandlerBase

class Handler(Handler Base):
pass

and finally:

ROOT/Handlers/Default/HandlerFactory. py contains:

from Handlers.Defaul t.Handlers import Handler

class HandlerFactory( object):

def makeHandler(sel f,command):
print 'HERE'
return Handler()




.... when I start main.py, I get:

Traceback (most recent call last):
File "main.py", line 8, in ?
main()
File "main.py", line 5, in main
handler = HandlerFactory( ).makeHandler(c ommand)
File "c:\ROOT\Handle rs\HandlerFacto ry.py", line 6, in HandlerFactory
import Handlers.Defaul t.HandlerFactor y
ImportError: No module named Default.Handler Factory


Using a bit different structure (with relative imports), I also had an
ImportError in ROOT/Handlers/Default/Handlers.py


I guess there is something I do not understand in the way Python looks for
the correct file in a package...

Can someone give me some explanations about what is happening here ?
And a way to solve that ?

Thanks for any help,




--
Stéphane Ninin
stefnin@alussin an.org

[Stéphane Ninin]

Re: import problems in packages

Also sprach Stéphane Ninin :
[color=blue]
>
>
> ... when I start main.py, I get:
>
> Traceback (most recent call last):
> File "main.py", line 8, in ?
> main()
> File "main.py", line 5, in main
> handler = HandlerFactory( ).makeHandler(c ommand)
> File "c:\ROOT\Handle rs\HandlerFacto ry.py", line 6, in HandlerFactory
> import Handlers.Defaul t.HandlerFactor y
> ImportError: No module named Default.Handler Factory
>[/color]

I forgot to mention: I am using Python 2.4.1

[Peter Hansen]

Re: import problems in packages

Stéphane Ninin wrote:[color=blue]
> Traceback (most recent call last):
> File "main.py", line 8, in ?
> main()
> File "main.py", line 5, in main
> handler = HandlerFactory( ).makeHandler(c ommand)
> File "c:\ROOT\Handle rs\HandlerFacto ry.py", line 6, in HandlerFactory
> import Handlers.Defaul t.HandlerFactor y
> ImportError: No module named Default.Handler Factory[/color]

Are you sure that's right? You asked it to import
Handlers.Defaul t.HandlerFactor y but it is apparently importing just
Default.Handler Factory instead? This seems unexpected to me, though
perhaps it can happen in certain situations. It's a hint, anyway.

Are the earlier four lines which you did show us relevant? (i.e. if
that's line six, what was on lines one, two, three, and four?)

-Peter

[Peter Otten]

Re: import problems in packages

Stéphane Ninin wrote:
[color=blue]
> Also sprach Stéphane Ninin :[/color]

Sollte es denn möglich sein! Dieser alte Heilige hat in seinem Walde noch
Nichts davon gehört... that intra-package import takes precedence over
absolute import!
[color=blue]
> Here is the basic structure of the code (I have reduced it first).[/color]

And nicely so. Not letting similar names for modules, packages and classes
abound might have been a good idea, too.
[color=blue]
> I have an ImportError problem, which is probably correct,
> but I do not understand it. And how to fix it...[/color]
[color=blue]
> ROOT:
> /main.py
> /Handlers/__init__.py (empty)
> /Handlers/Handlers.py
> /Handlers/HandlerFactory. py
> /Handlers/Default/__init__.py (empty)
> /Handlers/Default/Handlers.py
> /Handlers/Default/HandlerFactory. py[/color]
[color=blue]
> ROOT/main.py contains:
> from Handlers.Handle rFactory import HandlerFactory[/color]

works and triggers
[color=blue]
> ROOT/Handlers/HandlerFactory. py contains:
> import Handlers.Defaul t.HandlerFactor y[/color]

which tries to import

ROOT/Handlers/Handlers/Default/HandlerFactory. py, but unfortunately
ROOT/Handlers/Handlers[.py] is not a package and therefore doesn't contain
a Default package. Currently, when you have

amodule.py
apackage/amodule.py
apackage/anothermodule.p y

and try to import amodule into anothermodule, there is no way to tell Python
that you mean amodule.py and not apackage/anmodule.py.

Peter