dir() 函数
内置的函数 dir() 可以找到模块内定义的所有名称。以一个字符串列表的形式返回:
>>>import fibo, sys
>>> dir(fibo)
['__name__','fib','fib2']
>>> dir(sys)
['__displayhook__','__doc__','__excepthook__','__loader__','__name__',
'__package__','__stderr__','__stdin__','__stdout__',
'_clear_type_cache','_current_frames','_debugmallocstats','_getframe',
'_home','_mercurial','_xoptions','abiflags','api_version','argv',
'base_exec_prefix','base_prefix','builtin_module_names','byteorder',
'call_tracing','callstats','copyright','displayhook',
'dont_write_bytecode','exc_info','excepthook','exec_prefix',
'executable','exit','flags','float_info','float_repr_style',
'getcheckinterval','getdefaultencoding','getdlopenflags',
'getfilesystemencoding','getobjects','getprofile','getrecursionlimit',
'getrefcount','getsizeof','getswitchinterval','gettotalrefcount',
'gettrace','hash_info','hexversion','implementation','int_info',
'intern','maxsize','maxunicode','meta_path','modules','path',
'path_hooks','path_importer_cache','platform','prefix','ps1',
'setcheckinterval','setdlopenflags','setprofile','setrecursionlimit',
'setswitchinterval','settrace','stderr','stdin','stdout',
'thread_info','version','version_info','warnoptions']
如果没有给定参数，那么 dir() 函数会罗列出当前定义的所有名称:
>>> a =[1,2,3,4,5]
>>>import fibo
>>> fib = fibo.fib
>>> dir()# 得到一个当前模块中定义的属性列表
['__builtins__','__name__','a','fib','fibo','sys']
>>> a =5# 建立一个新的变量 'a'
>>> dir()
['__builtins__','__doc__','__name__','a','sys']
>>>
>>>del a # 删除变量名a
>>>
>>> dir()
['__builtins__','__doc__','__name__','sys']
>>>
