Python如何使用vars返回對象的屬性列表
英文文檔:
vars([object])
Return the __dict__ attribute for a module, class, instance, or any other object with a __dict__ attribute.Objects such as modules and instances have an updateable __dict__ attribute; however, other objects may have write restrictions on their __dict__ attributes (for example, classes use a dictproxy to prevent direct dictionary updates).Without an argument, vars() acts like locals(). Note, the locals dictionary is only useful for reads since updates to the locals dictionary are ignored.
返回當前作用域內的局部變量和其值組成的字典,或者返回對象的屬性列表
說明
1. 當函數不接收參數時,其功能和locals函數一樣,返回當前作用域內的局部變量。
#不帶參數功能和locals函數一樣>>> v1 = vars()>>> l1 = locals()>>> v1{’__name__’: ’__main__’, ’__builtins__’: <module ’builtins’ (built-in)>, ’v1’: {...}, ’l1’: {...}, ’__spec__’: None, ’__doc__’: None, ’__package__’: None, ’__loader__’: <class ’_frozen_importlib.BuiltinImporter’>}>>> l1{’__name__’: ’__main__’, ’__builtins__’: <module ’builtins’ (built-in)>, ’v1’: {...}, ’l1’: {...}, ’__spec__’: None, ’__doc__’: None, ’__package__’: None, ’__loader__’: <class ’_frozen_importlib.BuiltinImporter’>}
2. 當函數接收一個參數時,參數可以是模塊、類、類實例,或者定義了__dict__屬性的對象。
#作用于模塊>>> import time>>> vars(time){’gmtime’: <built-in function gmtime>, ’tzname’: (’Öйú±ê׼ʱ¼ä’, ’ÖйúÏÄÁîʱ’), ’timezone’: -28800, ’struct_time’: <class ’time.struct_time’>, ’ctime’: <built-in function ctime>, ’perf_counter’: <built-in function perf_counter>, ’mktime’: <built-in function mktime>, ’localtime’: <built-in function localtime>, ’time’: <built-in function time>, ’__package__’: ’’, ’altzone’: -32400, ’clock’: <built-in function clock>, ’strptime’: <built-in function strptime>, ’monotonic’: <built-in function monotonic>, ’__loader__’: <class ’_frozen_importlib.BuiltinImporter’>, ’get_clock_info’: <built-in function get_clock_info>, ’sleep’: <built-in function sleep>, ’process_time’: <built-in function process_time>, ’__name__’: ’time’, ’_STRUCT_TM_ITEMS’: 9, ’__spec__’: ModuleSpec(name=’time’, loader=<class ’_frozen_importlib.BuiltinImporter’>, origin=’built-in’), ’__doc__’: ’This module provides various functions to manipulate time values.nnThere are two standard representations of time. One is the numbernof seconds since the Epoch, in UTC (a.k.a. GMT). It may be an integernor a floating point number (to represent fractions of seconds).nThe Epoch is system-defined; on Unix, it is generally January 1st, 1970.nThe actual value can be retrieved by calling gmtime(0).nnThe other representation is a tuple of 9 integers giving local time.nThe tuple items are:n year (including century, e.g. 1998)n month (1-12)n day (1-31)n hours (0-23)n minutes (0-59)n seconds (0-59)n weekday (0-6, Monday is 0)n Julian day (day in the year, 1-366)n DST (Daylight Savings Time) flag (-1, 0 or 1)nIf the DST flag is 0, the time is given in the regular time zone;nif it is 1, the time is given in the DST time zone;nif it is -1, mktime() should guess based on the date and time.nnVariables:nntimezone -- difference in seconds between UTC and local standard timenaltzone -- difference in seconds between UTC and local DST timendaylight -- whether local time should reflect DSTntzname -- tuple of (standard time zone name, DST time zone name)nnFunctions:nntime() -- return current time in seconds since the Epoch as a floatnclock() -- return CPU time since process start as a floatnsleep() -- delay for a number of seconds given as a floatngmtime() -- convert seconds since Epoch to UTC tuplenlocaltime() -- convert seconds since Epoch to local time tuplenasctime() -- convert time tuple to stringnctime() -- convert time in seconds to stringnmktime() -- convert local time tuple to seconds since Epochnstrftime() -- convert time tuple to string according to format specificationnstrptime() -- parse string to time tuple according to format specificationntzset() -- change the local timezone’, ’strftime’: <built-in function strftime>, ’asctime’: <built-in function asctime>, ’daylight’: 0}#作用于類>>> vars(slice)mappingproxy({’__ne__’: <slot wrapper ’__ne__’ of ’slice’ objects>, ’__getattribute__’: <slot wrapper ’__getattribute__’ of ’slice’ objects>, ’__reduce__’: <method ’__reduce__’ of ’slice’ objects>, ’start’: <member ’start’ of ’slice’ objects>, ’indices’: <method ’indices’ of ’slice’ objects>, ’__ge__’: <slot wrapper ’__ge__’ of ’slice’ objects>, ’stop’: <member ’stop’ of ’slice’ objects>, ’__eq__’: <slot wrapper ’__eq__’ of ’slice’ objects>, ’step’: <member ’step’ of ’slice’ objects>, ’__hash__’: None, ’__doc__’: ’slice(stop)nslice(start, stop[, step])nnCreate a slice object. This is used for extended slicing (e.g. a[0:10:2]).’, ’__repr__’: <slot wrapper ’__repr__’ of ’slice’ objects>, ’__le__’: <slot wrapper ’__le__’ of ’slice’ objects>, ’__gt__’: <slot wrapper ’__gt__’ of ’slice’ objects>, ’__new__’: <built-in method __new__ of type object at 0x6A91B420>, ’__lt__’: <slot wrapper ’__lt__’ of ’slice’ objects>})#作用于類實例>>> class A(object): pass>>> a.__dict__{}>>> vars(a){}>>> a.name = ’Kim’>>> a.__dict__{’name’: ’Kim’}>>> vars(a){’name’: ’Kim’}
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