python模块-os,sys

搜索路径

Sys.argv[]是用来获取命令行参数的，sys.argv[0]表示代码本身文件路径，所以参数从1开始路径搜索
- 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

>>> import sys>>> sys.path[' ',    '/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']

程序执行时导入模块路径

>>> sys.path.insert(0,"/home/python/xxxx")   # 可以确保先搜索这个路径>>> sys.path ['/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']

操作系统接口

# 如果存在某个路径，则不添加if not os.path.exists('./path/test'):    os.makedirs('./path/test')# 将目录合并在一起my_path = os.path.join('./path/test','ok')  # ./paht/test/ok# 目录下的文件for file in os.listdir(file_dir):    print file   # cat.jpg