import vs. from module import *

[ggpf000]

I defined my own module <folder1>/<module1> and inside I <module1>, defined <function1>.

Now I import using import statement and call function1, it wont work.
But built-in package/lib import works.

import <module1>
import os
....
os.system()
call <function1()> <----- fails here
If I do following, then it works:

from <module1> import *
call <function1()>

What are difference between these statement such that import does not work for user-defined lib.

---

looks like i figured out during the post. :)

[metulburr]

import <module1>
import os
....
os.system()
call <function1()> <----- fails here

you need to do

<module1>.<function1()>

see this tutorial for more info
http://python-forum.io/Thread-Basic-Modules-part-1
you should also avoid star imports
http://python-forum.io/Thread-Namespace-...th-imports

[nilamo]

One uses namespacing, and the other pollutes the current namespace. "from _x_ import *" shouldn't ever be used. I'd love to hear some arguments for why people like it, but I'll still probably disagree with you :p

[Larz60+]

From David Beazley:

import always executes the entire file

http://www.dabeaz.com/modulepackage/ModulePackage.pdf

page 22

Not saying I agree, but it's hard not to agree with the Guru

[nilamo]

From David Beazley:

import always executes the entire file

http://www.dabeaz.com/modulepackage/ModulePackage.pdf

page 22

Not saying I agree, but it's hard not to agree with the Guru

I've been reading through it, and by far the most interesting things are the __main__.py files, and python zip executables (https://www.python.org/dev/peps/pep-0441/).