sys « Buildin Module « Python Tutorial

14.16.1.The list of search path can be found in the path variable in the sys module:
14.16.2.stdin of the sys module is a file object
14.16.3.sys module has the stdout and stderr attributes that point to files used for standard output and standard error output.
14.16.4.Using sys.modules
14.16.5.Redirecting Output
14.16.6.Redirecting Error Information
14.16.7.Printing to stderr
14.16.8.os.system(command) executes a system function as if it were in a subshell
14.16.9.sys.exit() and SystemExit

14.16.11.Append path to system path