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July 21st, 2003, 01:20 PM

SolarBear

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import vs. from

I was reading a Tkinter tutorial and I've noticed they use

Code:

from Tkinter import *

instead of the usual

Code:

import Tkinter

Is there any difference, or is it equivalent ?

July 21st, 2003, 01:37 PM

percivall

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When you do 'import Tkinter' you will access all the data objects through the Tkinter namespace. When you do a 'from Tkinter import *', you import all non-private data objects into your current namespace. Normally you shouldn't use 'from <something> import *', because it pollutes the namespace; but practicality beats purity...

July 21st, 2003, 01:37 PM

Scorpions4ever

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I haven't hacked in python for a while, but IIRC, the difference between this statement:
from somemodule import *
and this statement:
import somemodule

is that the first one imports all the functions implicitly within the namespace, whereas with the second one only public functions/objects are imported, so you may still have to qualify functions and objects with the module name, when calling them. For example:

Code:

#!/usr/bin/python
from sys import *

print "Hello world"
exit(1)

and

Code:

#!/usr/bin/python
import sys

print "Hello world"
sys.exit(1)

Notice that in the first case, I don't have to qualify exit(), but in the second case, I do.

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Last edited by Scorpions4ever : July 21st, 2003 at 01:39 PM.

July 21st, 2003, 01:41 PM

netytan

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where they both do roughly the same thing (program wise) its really just a personal choice.

from module import functions - imports the module and allows access to its functions/classes without the use of the module name prefix.

import module - import the module for use. My personal favourate simply because its easier to read.

Hope this helps,
Mark.

August 7th, 2003, 06:57 AM

telex4

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Just thought I'd add my own opinion here

I'd always go with "import module", since it makes reading the code easier (because you always know that "sys.exit()" is a sys method, not a builtin or one of your own), and because it means you don't accidentally overwrite your own functions/methods when importing lots of modules.

Keeps namespace nice and tidy

And if you do use "from module import *", try to explictly import particular functions/methods instead, since it will take up less memory and again be safer/nicer (i.e. "from module import x, y, z").

August 7th, 2003, 01:34 PM

percivall

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Personally, I would do:

Code:

import Tkinter as tk

to make the the code a little less excessively expressive.

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