1 import导入模块

1. import 搜索路径

import sys
sys.path

In [1]: import sys

In [2]: sys.path
Out[2]: 
['',
 '/usr/bin',
 '/usr/lib/python3.4',
 '/usr/lib/python3.4/plat-x86_64-linux-gnu',
 '/usr/lib/python3.4/lib-dynload',
 '/usr/local/lib/python3.4/dist-packages',
 '/usr/lib/python3/dist-packages',
 '/usr/lib/python3/dist-packages/IPython/extensions']

In [3]:

路径搜索

• 从上面列出的目录里依次查找要导入的模块文件
• ' ' 表示当前路径

程序执行时导入模块路径

sys.path.append('/home/itcast/xxx')
sys.path.insert(0, '/home/itcast/xxx')    #可以确保先搜索这个路径

In [37]: sys.path.insert(0,"/home/python/xxxx")
In [38]: sys.path
Out[38]: 
['/home/python/xxxx',
 '',
 '/usr/bin',
 '/usr/lib/python35.zip',
 '/usr/lib/python3.5',
 '/usr/lib/python3.5/plat-x86_64-linux-gnu',
 '/usr/lib/python3.5/lib-dynload',
 '/usr/local/lib/python3.5/dist-packages',
 '/usr/lib/python3/dist-packages',
 '/usr/lib/python3/dist-packages/IPython/extensions',
 '/home/python/.ipython']

2. 重新导入模块

模块被导入后，import module不能重新导入模块，重新导入需用

import imp
imp.reload(module)