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From: Dan Strohl <D.Strohl@F5.com>
Newsgroups: comp.lang.python
Subject: RE: does the order in which the modules are placed in a file matters ?
Date: Wed, 16 Dec 2015 16:42:01 +0000
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For the general modules it doesn't matter, however using if you are using a=
ny non-standard packages, and If there are duplicate names in any of the mo=
dules and if you import them with a "*" (as some packages suggest), it can =
cause you to end up referring to an object you were not intending to.

For example, if you have found a package called "foo", and the instructions=
 on it are to import it as:

from foo import *

Then you have another package called "bar" with the same instructions... so=
 now you have:

from foo import *
from bar import *

In both of these there is a class called "snafu", when you do this:

from foo import *
from bar import *

SITUATION =3D snafu()

You are going to get bar.snafu(), not foo.snafu()

This can of course be gotten around by doing:

import foo
import bar

SITUATION =3D foo.snafu()

(or a number of other approaches using "as" etc...)

Note, using * is dis-recommended, though pretty often done, for more inform=
ation on using *, see: https://docs.python.org/2/tutorial/modules.html#impo=
rting-from-a-package=20

Dan Strohl


-----Original Message-----
From: Python-list [mailto:python-list-bounces+d.strohl=3Df5.com@python.org]=
 On Behalf Of Chris Angelico
Sent: Wednesday, December 16, 2015 8:14 AM
Cc: python-list@python.org
Subject: Re: does the order in which the modules are placed in a file matte=
rs ?

On Thu, Dec 17, 2015 at 3:09 AM, Ganesh Pal <ganesh1pal@gmail.com> wrote:
> Iam on python 2.7 and linux .I need to know if we need to place the=20
> modules  in a particular or it doesn't matter at all
>
> order while writing the program
>
> For Example
>
> import os
> import shlex
> import subprocess
> import time
> import sys
> import logging
> import  plaftform.cluster
> from util import run

The order of the import statements is the order the modules will get loaded=
 up. As a general rule this won't matter; when it comes to standard library=
 modules, you can generally assume that you can put them in any order witho=
ut it making any difference. It's common to order them in some aestheticall=
y-pleasing way (maybe alphabetical order, or maybe sort them by the length =
of the name - whatever you like).

There is a broad convention that standard library modules get imported firs=
t, and modules that are part of the current project get imported afterwards=
. But even that doesn't usually matter very much.

ChrisA
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