是否有一种方法可以获取类实例上存在的属性列表?

class new_class():
    def __init__(self, number):
        self.multi = int(number) * 2
        self.str = str(number)

a = new_class(2)
print(', '.join(a.SOMETHING))

期望的结果是输出"multi, str"。我希望它能看到脚本各个部分的当前属性。


当前回答

请参见以下Python shell脚本执行顺序,它将给出从创建类到提取实例字段名的解决方案。

>>> class Details:
...       def __init__(self,name,age):
...           self.name=name
...           self.age =age
...       def show_details(self):
...           if self.name:
...              print "Name : ",self.name
...           else:
...              print "Name : ","_"
...           if self.age:
...              if self.age>0:
...                 print "Age  : ",self.age
...              else:
...                 print "Age can't be -ve"
...           else:
...              print "Age  : ","_"
... 
>>> my_details = Details("Rishikesh",24)
>>> 
>>> print my_details
<__main__.Details instance at 0x10e2e77e8>
>>> 
>>> print my_details.name
Rishikesh
>>> print my_details.age
24
>>> 
>>> my_details.show_details()
Name :  Rishikesh
Age  :  24
>>> 
>>> person1 = Details("",34)
>>> person1.name
''
>>> person1.age
34
>>> person1.show_details
<bound method Details.show_details of <__main__.Details instance at 0x10e2e7758>>
>>> 
>>> person1.show_details()
Name :  _
Age  :  34
>>>
>>> person2 = Details("Rob Pike",0)
>>> person2.name
'Rob Pike'
>>> 
>>> person2.age
0
>>> 
>>> person2.show_details()
Name :  Rob Pike
Age  :  _
>>> 
>>> person3 = Details("Rob Pike",-45)
>>> 
>>> person3.name
'Rob Pike'
>>> 
>>> person3.age
-45
>>> 
>>> person3.show_details()
Name :  Rob Pike
Age can't be -ve
>>>
>>> person3.__dict__
{'age': -45, 'name': 'Rob Pike'}
>>>
>>> person3.__dict__.keys()
['age', 'name']
>>>
>>> person3.__dict__.values()
[-45, 'Rob Pike']
>>>

其他回答

attributes_list = [attribute for attribute in dir(obj) if attribute[0].islower()]

获取对象的属性

class new_class():
    def __init__(self, number):
    self.multi = int(number) * 2
    self.str = str(number)

new_object = new_class(2)                
print(dir(new_object))                   #total list attributes of new_object
attr_value = new_object.__dict__         
print(attr_value)                        #Dictionary of attribute and value for new_class                   

for attr in attr_value:                  #attributes on  new_class
    print(attr)

输出

['__class__', '__delattr__', '__dict__', '__dir__', '__doc__','__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', 'multi', 'str']

{'multi': 4, 'str': '2'}

multi
str
>>> ', '.join(i for i in dir(a) if not i.startswith('__'))
'multi, str'

这当然会打印类定义中的任何方法或属性。你可以通过将i.startwith('__')更改为i.startwith('_')来排除“私有”方法。

检查模块:

inspect模块提供了几个有用的函数来帮助获取 有关活动对象的信息,如模块、类、方法、 函数、回溯、帧对象和代码对象。


使用getmembers()可以看到类的所有属性及其值。要排除私有或受保护的属性,请使用. startwith('_')。要排除方法或函数,请使用inspect.ismethod()或inspect.isfunction()。

import inspect


class NewClass(object):
    def __init__(self, number):
        self.multi = int(number) * 2
        self.str = str(number)

    def func_1(self):
        pass


inst = NewClass(2)

for i in inspect.getmembers(inst):
    # Ignores anything starting with underscore 
    # (that is, private and protected attributes)
    if not i[0].startswith('_'):
        # Ignores methods
        if not inspect.ismethod(i[1]):
            print(i)

注意,ismethod()用于i的第二个元素,因为第一个元素只是一个字符串(它的名字)。

跑题:类名使用CamelCase。

请参见以下Python shell脚本执行顺序,它将给出从创建类到提取实例字段名的解决方案。

>>> class Details:
...       def __init__(self,name,age):
...           self.name=name
...           self.age =age
...       def show_details(self):
...           if self.name:
...              print "Name : ",self.name
...           else:
...              print "Name : ","_"
...           if self.age:
...              if self.age>0:
...                 print "Age  : ",self.age
...              else:
...                 print "Age can't be -ve"
...           else:
...              print "Age  : ","_"
... 
>>> my_details = Details("Rishikesh",24)
>>> 
>>> print my_details
<__main__.Details instance at 0x10e2e77e8>
>>> 
>>> print my_details.name
Rishikesh
>>> print my_details.age
24
>>> 
>>> my_details.show_details()
Name :  Rishikesh
Age  :  24
>>> 
>>> person1 = Details("",34)
>>> person1.name
''
>>> person1.age
34
>>> person1.show_details
<bound method Details.show_details of <__main__.Details instance at 0x10e2e7758>>
>>> 
>>> person1.show_details()
Name :  _
Age  :  34
>>>
>>> person2 = Details("Rob Pike",0)
>>> person2.name
'Rob Pike'
>>> 
>>> person2.age
0
>>> 
>>> person2.show_details()
Name :  Rob Pike
Age  :  _
>>> 
>>> person3 = Details("Rob Pike",-45)
>>> 
>>> person3.name
'Rob Pike'
>>> 
>>> person3.age
-45
>>> 
>>> person3.show_details()
Name :  Rob Pike
Age can't be -ve
>>>
>>> person3.__dict__
{'age': -45, 'name': 'Rob Pike'}
>>>
>>> person3.__dict__.keys()
['age', 'name']
>>>
>>> person3.__dict__.values()
[-45, 'Rob Pike']
>>>