Python introductory learning---three ways to import modules and Chinese comments

Python has three module import functions
1. Use import to import modules import modname: A module refers to a code segment that can be used interactively or accessed from another Python program. Once a module is imported, any of its public functions, classes, or properties can be referenced. Modules can use the functionality of other modules in this way. Importing a module with the import statement establishes a reference to the module in the current namespace. This reference must use the full name, that is, when using a function defined in the imported module, the module must be included name. So you can’t just use funcname, but modname.funcname.

Note: You can add the following to make Python support Chinese comments

#coding:gbk或#coding:utf-8或##-*- coding : gbk -*-

Import the system module
For example, I created an m.py file in the home directory, and we imported it Many system modules, such as time, string, etc. This is similar to include in c++

#!/bin/env python  import time   
import stringimport reimport socketimport threading
time.sleep(10)print "java"

Import the private module

m.py file

#!/bin/env python
#coding:gbk 
#coding:utf-8
#上面的加载是支持中文注释
def plus(a ,b):
#"""XXX""" 是函数的说明或使用  
"""this is a test +"""
a = a+b
return a+b

Use import to load the m.py module to load
#!/bin/env python #coding:gbk #coding:utf-8 "Use the sys module to import the path of the specified Python file" import sys sys.path.append("./") "Another way to import Python files"
from m import plus
print plus(12,3)

print help(plus)

from modname import funcname from modname import fa, fb, fc or from modname import * The difference from the first method: funcname is directly imported into the local name space, so it can be used directly without the need to add module name restrictions* Indicates that all public objects of this module are imported into the current namespace, that is, anything that does not start with "_" will be imported. modname is not defined, so modname.funcname does not work. And, if funcname is already defined, it will be replaced by the new version (the version in the imported module). If funcname is changed to point to another object, modname cannot but notice it. Suggestions:

1) If you want to access the module's properties and methods frequently and don't want to type the module name over and over again, use from module import 2) If you want to selectively import certain properties and methods without For others, use from module import 3) If the module contains attributes and methods with the same name as one of your modules, you must use import module to avoid name conflicts 4) Use from module import * as little as possible because it determines a special function or where the properties come from is somewhat difficult, and makes debugging and refactoring more difficult.

#!/bin/env python
#!/bin/env python
#coding:gbk
#coding:utf-8
"利用sys模块导入指定Python文件的路径"
import sys
sys.path.append("./")
"另外一种导入Python文件"
from m import plus
print plus(12,3)
print help(plus)

3. Use the introverted function import. In addition to the previous two methods of using the import keyword, we can also use the built-in function import() to import modules. The difference between the two is that import must be followed by a type, while the parameter of import() is a string. This string may come from the configuration file or be the result of an expression calculation. For example, mymodule = import ('module_name') Notes: 1) The contents of the module are placed in a module file. For example, the contents of mymodule should be placed in a mymodule.py in the PYTHONPATH directory, except for those implemented in C. 2) The package can be Several module namespaces are organized, for example, A.b represents a submodule b in package A

#!/bin/env python
#coding:gbk
#coding:utf-8
"利用sys模块导入指定Python文件的路径"
import sys
sys.path.append("./")
"另外一种导入Python文件"
my = __import__("m")
print my.plus(12,3)
print help(my.plus)

Reference:

１, http://www.cnblogs.com/allenblogs/archive/2011/11/15 /2055149.html

２、http://blog.csdn.net/chenguolinblog/article/details/11521611