[Python] Modules 사용에 대한 용어 정의

Modules are processed with two new statements and one important built-in function we explore here:

 

import

Lets a client fetch a module as a whole

from

Allows clients to fetch particular names from a module

reload

Provides a way to reload a module's code without stopping Python

 

 

Why Use Modules?

Let's start with the obvious first question: why should we care about modules? The short answer is that they provide an easy way to organize components into a system. But from an abstract perspective, modules have at least three roles:

 

Code reuse

As we saw in Chapter 1, modules let us save code in files permanently.* Unlike code you

type at the Python interactive prompt (which goes away when you exit Python), code in

module files is persistent—it can be reloaded and rerun as many times as needed. More to

the point, modules are a place to define names (called attributes) that may be referenced

by external clients.

 

System namespace partitioning

Modules are also the highest-level program organization unit in Python. As we'll see,

everything ''lives" in a module; code you execute and some objects you create are always

implicitly enclosed by a module. Because of that, modules are a natural tool for grouping

system components.

 

Implementing shared services or data

From a functional perspective, modules also come in handy for implementing components

shared across a system, and hence only require a single copy. For instance, if you need to

provide a global data structure that's used by more than one function, you can code it in a

module that's imported by many clients.

 

 

Example

'''
Created on 2010. 5. 5.

@author: all
'''
def printer(x):
    print x # modules attribute

'''
Created on 2010. 5. 5.

@author: all
'''
import modules1

modules1.printer( ' Hello World!')

'''Created on 2010. 5. 5.

@author: all
'''
#import modules1
 
#modules1.printer( ' Hello World!')

from modules1 import printer

printer('Hello World')