sys提供对解释器使用或维护的一些变量以及与解释器强烈交互的函数的访问。想了解该模块
建议看官方的详细的说明，链接地址为：https://docs.python.org/2/library/sys.html。该模
块的源码为：
# encoding: utf-8 # module sys # from (built-in) # by generator 1.145 """ This module provides access to some objects used or maintained by the interpreter and to functions that interact strongly with the interpreter. Dynamic objects: argv -- command line arguments; argv[0] is the script pathname if known path -- module search path; path[0] is the script directory, else '' modules -- dictionary of loaded modules displayhook -- called to show results in an interactive session excepthook -- called to handle any uncaught exception other than SystemExit To customize printing in an interactive session or to install a custom top-level exception handler, assign other functions to replace these. exitfunc -- if sys.exitfunc exists, this routine is called when Python exits Assigning to sys.exitfunc is deprecated; use the atexit module instead. stdin -- standard input file object; used by raw_input() and input() stdout -- standard output file object; used by the print statement stderr -- standard error object; used for error messages By assigning other file objects (or objects that behave like files) to these, it is possible to redirect all of the interpreter's I/O. last_type -- type of last uncaught exception last_value -- value of last uncaught exception last_traceback -- traceback of last uncaught exception These three are only available in an interactive session after a traceback has been printed. exc_type -- type of exception currently being handled exc_value -- value of exception currently being handled exc_traceback -- traceback of exception currently being handled The function exc_info() should be used instead of these three, because it is thread-safe. Static objects: float_info -- a dict with information about the float inplementation. long_info -- a struct sequence with information about the long implementation. maxint -- the largest supported integer (the smallest is -maxint-1) maxsize -- the largest supported length of containers. maxunicode -- the largest supported character builtin_module_names -- tuple of module names built into this interpreter version -- the version of this interpreter as a string version_info -- version information as a named tuple hexversion -- version information encoded as a single integer copyright -- copyright notice pertaining to this interpreter platform -- platform identifier executable -- absolute path of the executable binary of the Python interpreter prefix -- prefix used to find the Python library exec_prefix -- prefix used to find the machine-specific Python library float_repr_style -- string indicating the style of repr() output for floats dllhandle -- [Windows only] integer handle of the Python DLL winver -- [Windows only] version number of the Python DLL __stdin__ -- the original stdin; don't touch! __stdout__ -- the original stdout; don't touch! __stderr__ -- the original stderr; don't touch! __displayhook__ -- the original displayhook; don't touch! __excepthook__ -- the original excepthook; don't touch! Functions: displayhook() -- print an object to the screen, and save it in __builtin__._ excepthook() -- print an exception and its traceback to sys.stderr exc_info() -- return thread-safe information about the current exception exc_clear() -- clear the exception state for the current thread exit() -- exit the interpreter by raising SystemExit getdlopenflags() -- returns flags to be used for dlopen() calls getprofile() -- get the global profiling function getrefcount() -- return the reference count for an object (plus one :-) getrecursionlimit() -- return the max recursion depth for the interpreter getsizeof() -- return the size of an object in bytes gettrace() -- get the global debug tracing function setcheckinterval() -- control how often the interpreter checks for events setdlopenflags() -- set the flags to be used for dlopen() calls setprofile() -- set the global profiling function setrecursionlimit() -- set the max recursion depth for the interpreter settrace() -- set the global debug tracing function """ # no imports # Variables with simple values api_version = 1013 byteorder = 'little' copyright = 'Copyright (c) 2001-2015 Python Software Foundation.\nAll Rights Reserved.\n\nCopyright (c) 2000 BeOpen.com.\nAll Rights Reserved.\n\nCopyright (c) 1995-2001 Corporation for National Research Initiatives.\nAll Rights Reserved.\n\nCopyright (c) 1991-1995 Stichting Mathematisch Centrum, Amsterdam.\nAll Rights Reserved.' dllhandle = 1677983744L dont_write_bytecode = True exc_type = None executable = 'C:\\Python27\\python.exe' exec_prefix = 'C:\\Python27' float_repr_style = 'short' hexversion = 34016240 maxint = 2147483647 maxsize = 9223372036854775807L maxunicode = 65535 platform = 'win32' prefix = 'C:\\Python27' py3kwarning = False version = '2.7.11 (v2.7.11:6d1b6a68f775, Dec 5 2015, 20:40:30) [MSC v.1500 64 bit (AMD64)]' winver = '2.7-32' __egginsert = 3 __plen = 9 # functions def callstats(): # real signature unknown; restored from __doc__ """ callstats() -> tuple of integers Return a tuple of function call statistics, if CALL_PROFILE was defined when Python was built. Otherwise, return None. When enabled, this function returns detailed, implementation-specific details about the number of function calls executed. The return value is a 11-tuple where the entries in the tuple are counts of: 0. all function calls 1. calls to PyFunction_Type objects 2. PyFunction calls that do not create an argument tuple 3. PyFunction calls that do not create an argument tuple and bypass PyEval_EvalCodeEx() 4. PyMethod calls 5. PyMethod calls on bound methods 6. PyType calls 7. PyCFunction calls 8. generator calls 9. All other calls 10. Number of stack pops performed by call_function() """ return () def call_tracing(func, args): # real signature unknown; restored from __doc__ """ call_tracing(func, args) -> object Call func(*args), while tracing is enabled. The tracing state is saved, and restored afterwards. This is intended to be called from a debugger from a checkpoint, to recursively debug some other code. """ return object() def displayhook(p_object): # real signature unknown; restored from __doc__ """ displayhook(object) -> None Print an object to sys.stdout and also save it in __builtin__._ """ pass def excepthook(exctype, value, traceback): # real signature unknown; restored from __doc__ """ excepthook(exctype, value, traceback) -> None Handle an exception by displaying it with a traceback on sys.stderr. """ pass def exc_clear(): # real signature unknown; restored from __doc__ """ exc_clear() -> None Clear global information on the current exception. Subsequent calls to exc_info() will return (None,None,None) until another exception is raised in the current thread or the execution stack returns to a frame where another exception is being handled. """ pass def exc_info(): # real signature unknown; restored from __doc__ """ exc_info() -> (type, value, traceback) Return information about the most recent exception caught by an except clause in the current stack frame or in an older stack frame. """ pass def exit(status=None): # real signature unknown; restored from __doc__ """ exit([status]) Exit the interpreter by raising SystemExit(status). If the status is omitted or None, it defaults to zero (i.e., success). If the status is an integer, it will be used as the system exit status. If it is another kind of object, it will be printed and the system exit status will be one (i.e., failure). """ pass def exitfunc(): # reliably restored by inspect """ run any registered exit functions _exithandlers is traversed in reverse order so functions are executed last in, first out. """ pass def getcheckinterval(): # real signature unknown; restored from __doc__ """ getcheckinterval() -> current check interval; see setcheckinterval(). """ pass def getdefaultencoding(): # real signature unknown; restored from __doc__ """ getdefaultencoding() -> string Return the current default string encoding used by the Unicode implementation. """ return "" def getfilesystemencoding(): # real signature unknown; restored from __doc__ """ getfilesystemencoding() -> string Return the encoding used to convert Unicode filenames in operating system filenames. """ return "" def getprofile(): # real signature unknown; restored from __doc__ """ getprofile() Return the profiling function set with sys.setprofile. See the profiler chapter in the library manual. """ pass def getrecursionlimit(): # real signature unknown; restored from __doc__ """ getrecursionlimit() Return the current value of the recursion limit, the maximum depth of the Python interpreter stack. This limit prevents infinite recursion from causing an overflow of the C stack and crashing Python. """ pass def getrefcount(p_object): # real signature unknown; restored from __doc__ """ getrefcount(object) -> integer Return the reference count of object. The count returned is generally one higher than you might expect, because it includes the (temporary) reference as an argument to getrefcount(). """ return 0 def getsizeof(p_object, default): # real signature unknown; restored from __doc__ """ getsizeof(object, default) -> int Return the size of object in bytes. """ return 0 def gettrace(): # real signature unknown; restored from __doc__ """ gettrace() Return the global debug tracing function set with sys.settrace. See the debugger chapter in the library manual. """ pass def getwindowsversion(): # real signature unknown; restored from __doc__ """ getwindowsversion() Return information about the running version of Windows as a named tuple. The members are named: major, minor, build, platform, service_pack, service_pack_major, service_pack_minor, suite_mask, and product_type. For backward compatibility, only the first 5 items are available by indexing. All elements are numbers, except service_pack which is a string. Platform may be 0 for win32s, 1 for Windows 9x/ME, 2 for Windows NT/2000/XP/Vista/7, 3 for Windows CE. Product_type may be 1 for a workstation, 2 for a domain controller, 3 for a server. """ pass def setcheckinterval(n): # real signature unknown; restored from __doc__ """ setcheckinterval(n) Tell the Python interpreter to check for asynchronous events every n instructions. This also affects how often thread switches occur. """ pass def setprofile(function): # real signature unknown; restored from __doc__ """ setprofile(function) Set the profiling function. It will be called on each function call and return. See the profiler chapter in the library manual. """ pass def setrecursionlimit(n): # real signature unknown; restored from __doc__ """ setrecursionlimit(n) Set the maximum depth of the Python interpreter stack to n. This limit prevents infinite recursion from causing an overflow of the C stack and crashing Python. The highest possible limit is platform- dependent. """ pass def settrace(function): # real signature unknown; restored from __doc__ """ settrace(function) Set the global debug tracing function. It will be called on each function call. See the debugger chapter in the library manual. """ pass def _clear_type_cache(): # real signature unknown; restored from __doc__ """ _clear_type_cache() -> None Clear the internal type lookup cache. """ pass def _current_frames(): # real signature unknown; restored from __doc__ """ _current_frames() -> dictionary Return a dictionary mapping each current thread T's thread id to T's current stack frame. This function should be used for specialized purposes only. """ return {} def _getframe(depth=None): # real signature unknown; restored from __doc__ """ _getframe([depth]) -> frameobject Return a frame object from the call stack. If optional integer depth is given, return the frame object that many calls below the top of the stack. If that is deeper than the call stack, ValueError is raised. The default for depth is zero, returning the frame at the top of the call stack. This function should be used for internal and specialized purposes only. """ pass def __displayhook__(*args, **kwargs): # real signature unknown """ displayhook(object) -> None Print an object to sys.stdout and also save it in __builtin__._ """ pass def __excepthook__(*args, **kwargs): # real signature unknown """ excepthook(exctype, value, traceback) -> None Handle an exception by displaying it with a traceback on sys.stderr. """ pass # no classes # variables with complex values argv = [] # real value of type <type 'list'> skipped builtin_module_names = () # real value of type <type 'tuple'> skipped flags = None # (!) real value is '' float_info = None # (!) real value is '' long_info = None # (!) real value is '' meta_path = [] modules = {} # real value of type <type 'dict'> skipped path = [ 'D:\\Program Files\\JetBrains\\PyCharm 2017.1.2\\helpers', 'C:\\Python27\\lib\\site-packages\\robotframework-3.0-py2.7.egg', 'C:\\Python27\\lib\\site-packages\\robotframework_selenium2library-1.8.0-py2.7.egg', 'C:\\Python27\\lib\\site-packages\\selenium-2.53.2-py2.7.egg', 'C:\\Windows\\system32\\python27.zip', 'C:\\Python27\\DLLs', 'C:\\Python27\\lib', 'C:\\Python27\\lib\\plat-win', 'C:\\Python27\\lib\\lib-tk', 'C:\\Python27', 'C:\\Users\\Administrator.lwp-PC\\AppData\\Roaming\\Python\\Python27\\site-packages', 'C:\\Python27\\lib\\site-packages', 'C:\\Python27\\lib\\site-packages\\PIL', 'C:\\Python27\\lib\\site-packages\\wx-2.8-msw-unicode', ] path_hooks = [ None, # (!) real value is '' ] path_importer_cache = {} # real value of type <type 'dict'> skipped stderr = open('') # real value of type <type 'file'> replaced stdin = open('') # real value of type <type 'file'> replaced stdout = open('') # real value of type <type 'file'> replaced subversion = ( 'CPython', '', '', ) version_info = None # (!) real value is '' warnoptions = [] _mercurial = ( 'CPython', 'v2.7.11', '6d1b6a68f775', ) __stderr__ = None # (!) real value is '' __stdin__ = None # (!) real value is '' __stdout__ = stdout # intermittent names exc_value = Exception() exc_traceback=None
下面具体来看该模块的使用和该模块中某些方法的具体应用，具体见如下的代码：
#!/usr/bin/env python # -*- coding:utf-8 -*- import sys print sys.argv #依据用户的输入进行传输的传递 if sys.argv[1]=='sleep': print u'去睡觉' else: print u'无所谓'
见执行该代码后的实际输出,传递的参数是"sleep"：
如果传递的参数不是sleep，我们看执行后的结果，见截图：
#!/usr/bin/env python # -*- coding:utf-8 -*- import sys print u'获取python解释程序的版本信息:',sys.version print u'获取最大的int值:',sys.maxint print u'获取操作系统平台名称:',sys.platform print u'返回模块的搜索路劲:\n' for item in sys.path: print item print u'模拟进度条的实现:\n' for i in range(10): sys.stdout.write('#') import time time.sleep(0.3) print u'\n读取屏幕的输入:\n' val=sys.stdin.readline()[:-1] print u'屏幕输入的内容为:',val
依据用户的输入参数，来创建一个目录，见实现的代码：
#!/usr/bin/env python # -*- coding:utf-8 -*- import sys import os os.mkdir(sys.argv[1])
实现在Q盘下创建一个sys的文件夹，也就是目录，见过程：
见创建的sys目录截图：
sys模块就总结到这，如果想深入对sys模块研究的同学，建议查看官方的详细文档，和官方的说明。