Best practices with import?

[Tom Bryan]

Alex wrote:

> Goodness, without import, python's close to useless.  

Well, of course.  But where to import?  What's the most common idiom?

import sys, os, string

or 

import sys
import os
import string

or 

import sys as _sys

and where Python programmers expect to see the imports?

> I'm not sure what advantage there might be to deleting module references
> in a function's scope just prior to leaving it.  I would have thought
> the reference was usually dropped at that point, anyway.

After digging at Google Groups, I think that it might have been a comment 
about importing and then deleting at the module level.  At least, I see 
that the timbot is still explaining why threading.py does this.

import sys
import time
import thread
import traceback
import StringIO

# Rename some stuff so "from threading import *" is safe

_sys = sys
del sys

_time = time.time
_sleep = time.sleep
del time

still-seeking-elightenment-ly yours
---Tom