sys module VS OS module

A, sys module

　　--sys module, which provides a number of functions and variables, so that some of the information we can get python parser, on behalf of the python parser operation

　　Common operations:

　　　　The introduction of import sys;

　　　　All current program module properties sys.modules introduced, returns a dictionary module name {:} module object;

　　　　Function sys.exit (print [information]) indicates to exit the current program;

　　　　Python sys.path is saved properties built and custom module search path, it returns a list.

Two, os module

　　- operating system modules can be accessed through the computer's operating system module

　　- the os.system function ( 'the operating system's command'), for example: os.system ( 'dir')

　　- Property os.enrivon return system environment variables, an ancestral