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Re: import in Python3.3

From Fabian von Romberg <fromberg100@hotmail.com>
Subject Re: import in Python3.3
Date 2013-03-24 20:39 -0500
References <mailman.3685.1364166787.2939.python-list@python.org> <514f9a0b$0$30001$c3e8da3$5496439d@news.astraweb.com>
Newsgroups comp.lang.python
Message-ID <mailman.3687.1364175588.2939.python-list@python.org> (permalink)

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Hi Steven,

thanks a lot for the explanation.

I will keep in mind not to use names for my modules that can shadow the standard library.

Regards,
Fabian

On 03/24/2013 07:27 PM, Steven D'Aprano wrote:
> On Sun, 24 Mar 2013 18:12:49 -0500, Fabian von Romberg wrote:
> 
>> Hi,
>>
>> I have a package name collections and inside of my package I want to
>> import the collections package from the standard library, but there is
>> name conflicts.
>>
>> How do I import explicitly from the standard library?
> 
> You can't. However, you can import explicitly from your package, or 
> implicitly by using a relative import.
> 
> Starting from Python 2.7, the "import" statement is always absolute. So 
> the line:
> 
>   import collections
> 
> will always find the first *top level* module or package "collections" in 
> the python search path. See below for an important proviso.
> 
> Inside your package, you can either use an explicit import like this:
> 
>   import mypackage.collections as collections
> 
> or use a relative import like this:
> 
>   from . import collections
> 
> Here is a concrete example. I create a package containing five files:
> 
> mypackage/
> +-- __init__.py
> +-- collections.py
> +-- absolute_import.py
> +-- explicit_import.py
> +-- relative_import.py
> 
> with the following content:
> 
> # absolute_import.py
> import collections
> 
> # explicit_import.py 
> import mypackage.collections as collections
> 
> # relative_import.py 
> from . import collections
> 
> 
> The other two files (collections.py and __init__.py) can be blank. Now, 
> from *outside* the package, I can do this:
> 
> 
> py> import mypackage.absolute_import
> py> import mypackage.explicit_import
> py> import mypackage.relative_import
> py> 
> py> mypackage.absolute_import.collections
> <module 'collections' from '/usr/local/lib/python3.3/collections/__init__.py'>
> py> mypackage.explicit_import.collections
> <module 'mypackage.collections' from './mypackage/collections.py'>
> py> mypackage.relative_import.collections
> <module 'mypackage.collections' from './mypackage/collections.py'>
> 
> 
> Of course "from mypackage import absolute_import" etc. will also work.
> 
> 
> However, beware: if you cd into the package directory, and then launch 
> Python, the current directory will contain a file "collections.py" which 
> will shadow the standard library collections.py. So don't do that.
> 
> 
> 

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Thread

import in Python3.3 Fabian von Romberg <fromberg100@hotmail.com> - 2013-03-24 18:12 -0500
  Re: import in Python3.3 Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-03-25 00:27 +0000
    Re: import in Python3.3 Fabian von Romberg <fromberg100@hotmail.com> - 2013-03-24 20:39 -0500
    Re: import in Python3.3 rocky <rocky@gnu.org> - 2013-03-25 20:49 -0700
      Re: import in Python3.3 Jerry Hill <malaclypse2@gmail.com> - 2013-03-26 12:33 -0400
        Re: import in Python3.3 rocky <rocky@gnu.org> - 2013-03-26 11:41 -0700
        Re: import in Python3.3 rocky <rocky@gnu.org> - 2013-03-26 11:41 -0700
        Re: import in Python3.3 Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-03-26 23:11 +0000

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