全面理解python命名空间字典

>>> class MySuper:
    s='梯阅线条'
    def m1(self):
        self.data1='MySuper'
>>> class MyClassA(MySuper):
    def __init__(self):
        self.data2='MyClassA'

# 类名.__dict__ 查看类的属性字典，
# 前后带双下划线的为内置属性 ， 其他为自定义属性        
>>> MySuper.__dict__.keys()
dict_keys(['__module__', 's', 'm1', '__dict__', '__weakref__', '__doc__'])
>>> msp=MySuper()
# 实例名.__dict__ 查看实例的属性字典，
# 实例无本身属性则为空。
>>> msp.__dict__.keys()
dict_keys([])
# 调用m1()通过self.属性=值，进行属性赋值
>>> msp.m1()
# 实例名.__dict__ 只返回实例赋值的属性，不返回类的属性
>>> msp.__dict__.keys()
dict_keys(['data1'])
# 类名.__dict__ 只返回类属性，不返回实例属性
>>> MySuper.__dict__.keys()
dict_keys(['__module__', 's', 'm1', '__dict__', '__weakref__', '__doc__'])
>>> msp2=MySuper()
# 每个实例有独立的属性字典
>>> msp2.__dict__.keys()
dict_keys([])
# 创建实例时自动执行__init__()给实例属性赋值
>>> mca=MyClassA()
>>> mca.__dict__.keys()
dict_keys(['data2'])

>>> class MyClass:pass
>>> c1=MyClass()
>>> c1
<__main__.MyClass object at 0x03D19C50>
# __class__ 返回实例所属类
>>> c1.__class__
<class '__main__.MyClass'>
# 用返回的类创建实例对象
>>> c2=c1.__class__()
>>> c2
<__main__.MyClass object at 0x03D19CF0>

>>> class MyClass:pass
>>> c1=MyClass()
>>> c1=MyClass()
# __name__ 返回实例所属类的名字
>>> c1.__class__.__name__
'MyClass'

>>> class MyClass:pass
>>> class MyClassA(MyClass):pass
>>> class MyClassB():pass
>>> class MyClassC(MyClassA,MyClassB):pass
# __bases__ 返回直接超类组成的元组
>>> MyClassC.__bases__
(<class '__main__.MyClassB'>, <class '__main__.MyClassA'>)

>>> class MySuper:
    s='梯阅线条'
    def m1(self):
        self.data1='MySuper'

>>> class MyClassA(MySuper):
    def __init__(self):
        self.data2='MyClassA'

>>> msp1=MySuper()
>>> msp1.__dict__
{}
>>> msp1.__class__.__name__
'MySuper'
>>> msp1.m1()
>>> msp1.__dict__
{'data1': 'MySuper'}
>>> mca1=MyClassA()
>>> mca1.__dict__
{'data2': 'MyClassA'}
>>> mca1.__dict__
{'data2': 'MyClassA'}
>>> MySuper.__dict__.keys()
dict_keys(['__module__', 's', 'm1', '__dict__', '__weakref__', '__doc__'])
>>> mca1.m1()
>>> mca1.__dict__
{'data2': 'MyClassA', 'data1': 'MySuper'}
# 搜索s，从 MySuper.__dict__ 类命名空间获取
>>> mca1.s
'梯阅线条'
# 搜索 data1 和 data2 从 实例命名看空间获取
>>> mca1.data1
'MySuper'
>>> mca1.data2
'MyClassA'

>>> class MySuper:
    s='梯阅线条'
    def m1(self):
        self.data1='MySuper'

>>> class MyClassA(MySuper):
    def __init__(self):
        self.data2='MyClassA'
    
>>> msp1=MySuper()
# 类.__dict__.keys() 返回类属性
>>> MySuper.__dict__.keys()
dict_keys(['__module__', 's', 'm1', '__dict__', '__weakref__', '__doc__'])
# dir(类) 比 类.__dict__.keys() 多 系统属性
>>> dir(MySuper)
['__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__', 'm1', 's']
# dir(实例) 返回类属性
>>> dir(msp1)
['__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__', 'm1', 's']
# 实例.__dict__.keys() 不返回类属性 ， 返回实例属性 
>>> msp1.__dict__.keys()
dict_keys([])

# dir(类) 返回 超类的属性 
>>> dir(MyClassA)
['__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__', 'm1', 's']
# 类.__dict__.keys() 不返回超类属性
>>> MyClassA.__dict__.keys()
dict_keys(['__module__', '__init__', '__doc__'])
# dir(实例) 返回 超类的属性 
>>> dir(mca1)
['__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__', 'data2', 'm1', 's']
# 实例.__dict__.keys() 不返回超类属性
>>> mca1.__dict__.keys()
dict_keys(['data2'])

def classtree(cls,indent):
    print('| '* indent + '|-' + cls.__name__)
    # cls.__bases__
    for supercls in cls.__bases__:
        classtree(supercls,indent+1)

def instancetree(inst):
    print('Tree of {}'.format(inst))
    # inst.__class__ 实例所属类
    classtree(inst.__class__,0)
    
def selftest():
    class A:pass
    class B(A):pass
    class C(A):pass
    class D(B,C):pass
    class E:pass
    class F(D,E):pass
    instancetree(B())
    instancetree(F())
    
if __name__ == '__main__':
    selftest()
    
''' 运行结果    
E:\documents\F盘>python classtree.py
Tree of <__main__.selftest.<locals>.B object at 0x01978A30>
|-B
| |-A
| | |-object
Tree of <__main__.selftest.<locals>.F object at 0x01978A30>
|-F
| |-D
| | |-B
| | | |-A
| | | | |-object
| | |-C
| | | |-A
| | | | |-object
| |-E
| | |-object
'''

'''
模块文件名：docstr.py
模块开头的文档字符串
'''
S='梯阅线条'
def hellof(name):
    '''
    函数开头的文档字符串
    '''
    print('hello ',name)

class Student:
    '''
    类开头处的文档字符串
    '''
    def study(self):
        '''
        方法开头的文档字符串
        '''
        pass
    
# 查看不同对象的__doc__文档字符串
>>> path=r'E:\documents\F盘'
>>> import os
>>> os.chdir(path)
>>> import docstr
>>> dir(docstr)
['L', 'S', 'Student', '__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__spec__', 'hellof']
>>> print(docstr.__doc__)

模块文件名：docstr.py
模块开头的文档字符串
>>> print(docstr.hellof.__doc__)

    函数开头的文档字符串
>>> print(docstr.Student.__doc__)

    类开头处的文档字符串
>>> print(docstr.Student.study.__doc__)

        方法开头的文档字符串