我有两个类,一个是基类,第二个类需要从基类继承。我在这种情况下正确使用super()的问题。
当我创建我的课程TestService
时,它继承自ServiceMap
,因此我认为所需的MRO应该是:TestService - > ServiceMap - > OrderedDict。
这是否意味着我的初始化程序TestService
我应该致电super(ServiceMap, self).__init__(value=value, kwargs=None)
?然后初始化TestService类的其余部分? (如下所示)。或者我是否需要在每个继承的类中从ServiceMap
重新创建初始值设定项?我真的不想重新创建该代码,因为会有多种类型的服务继承自ServiceMap
类型。
请提供一些超级()指导!
由于
from collections import OrderedDict
from sys import version_info
from inspect import ismethod
import json
import six
import copy
class ServiceMap(OrderedDict):
_map = None
#----------------------------------------------------------------------
def __init__(self, value=None, **kwargs):
"""Initializer object"""
self._map = OrderedDict()
if value:
if isinstance(value, dict):
for k,v in six.iteritems(value):
if isinstance(v, dict):
v = ServiceMap(value=v)
self._map[k] = v
del k,v
if kwargs:
for k,v in six.iteritems(kwargs):
self._map[k] = v
#----------------------------------------------------------------------
def items(self):
return six.iteritems(self._map)
#----------------------------------------------------------------------
def iteritems(self):
return six.iteritems(self._map)
#----------------------------------------------------------------------
def __iter__(self):
return self._map.__iter__()
#----------------------------------------------------------------------
def next(self):
return self._map.next()
#----------------------------------------------------------------------
def __setitem__(self, k, v):
self._map[k] = v
#----------------------------------------------------------------------
def __getitem__(self, k):
if k not in self._map:
# if parameter k DNE, create a empty object as ServiceMap
self[k] = ServiceMap()
return self._map[k]
#----------------------------------------------------------------------
def __setattr__(self, k, v):
if k == '_map':
super(ServiceMap, self).__setattr__(k,v)
else:
self[k] = v
#----------------------------------------------------------------------
def __getattr__(self, k):
if k == '_map':
super(ServiceMap, self).__getattr__(k)
else:
return self[k]
#----------------------------------------------------------------------
def __delattr__(self, key):
return self._map.__delitem__(key)
#----------------------------------------------------------------------
def __contains__(self, k):
return self._map.__contains__(k)
#----------------------------------------------------------------------
def __str__(self):
"""represents the object as a string"""
return json.dumps(self.as_dictionary())
#----------------------------------------------------------------------
def __repr__(self):
return str(self)
#----------------------------------------------------------------------
def as_dictionary(self):
"""
recursively iterate the object inorder to conver the ServiceMap object
to a traditional dictionary type object."""
vals = {}
for k,v in self.items():
if type(v) is ServiceMap:
vals[k] = v.as_dictionary()
else:
vals[k] = v
del k,v
return vals
#----------------------------------------------------------------------
def values(self):
return self._map.values()
#----------------------------------------------------------------------
def __cmp__(self, value):
value = ServiceMap.compare(value)
return self._map.__cmp__(value)
#----------------------------------------------------------------------
def __eq__(self, value):
value = ServiceMap.compare(value)
if not isinstance(value, dict):
return False
return self._map.__eq__(value)
#----------------------------------------------------------------------
def __ge__(self, value):
value = ServiceMap.compare(value)
return self._map.__ge__(value)
#----------------------------------------------------------------------
def __gt__(self, value):
value = ServiceMap.compare(value)
return self._map.__gt__(value)
#----------------------------------------------------------------------
def __le__(self, value):
value = ServiceMap.compare(value)
return self._map.__le__(value)
#----------------------------------------------------------------------
def __lt__(self, value):
value = ServiceMap.compare(value)
return self._map.__lt__(value)
#----------------------------------------------------------------------
def __ne__(self, value):
value = ServiceMap.compare(value)
return self._map.__ne__(value)
#----------------------------------------------------------------------
def __delitem__(self, key):
return self._map.__delitem__(key)
#----------------------------------------------------------------------
def __len__(self):
return self._map.__len__()
#----------------------------------------------------------------------
def clear(self):
self._map.clear()
#----------------------------------------------------------------------
def copy(self):
return copy.deepcopy(self)
#----------------------------------------------------------------------
def get(self, key, default=None):
return self._map.get(key, default)
#----------------------------------------------------------------------
def has_key(self, key):
return key in self._map
#----------------------------------------------------------------------
def iterkeys(self):
return self._map.iterkeys()
#----------------------------------------------------------------------
def itervalues(self):
return self._map.itervalues()
#----------------------------------------------------------------------
def keys(self):
return self._map.keys()
#----------------------------------------------------------------------
def pop(self, key, default=None):
return self._map.pop(key, default)
#----------------------------------------------------------------------
def popitem(self):
return self._map.popitem()
#----------------------------------------------------------------------
def setdefault(self, key, default=None):
self._map.setdefault(key, default)
#----------------------------------------------------------------------
def update(self, *args, **kwargs):
if len(args) != 0:
self._map.update(*args)
self._map.update(kwargs)
#----------------------------------------------------------------------
def viewitems(self):
return self._map.viewitems()
#----------------------------------------------------------------------
def viewkeys(self):
return self._map.viewkeys()
#----------------------------------------------------------------------
def viewvalues(self):
return self._map.viewvalues()
#----------------------------------------------------------------------
@classmethod
def fromkeys(cls, seq, value=None):
"""
creates a ServiceMap object from a set of keys with default values
This allows the creation of template objects.
"""
val = ServiceMap()
val._map = OrderedDict.fromkeys(seq, value)
return val
#----------------------------------------------------------------------
@classmethod
def compare(self, value):
if type(value) is ServiceMap:
return value._map
else:
return value
class TestService(ServiceMap):
_con = None
_url = None
def __init__(self, url, connection, value=None):
super(ServiceMap, self).__init__(value=value)
self._url = None
self._con = None
答案 0 :(得分:1)
使用Python 3继承的简单方法是
class TestService(ServiceMap):
def __init__(self, value=None, **kwargs):
super().__init__(value, kwargs) #equivalent to ServiceMap.__init__(self,value, kwargs)
code_specific to this class()
这为您提供了一个“适当的”ServiceMap,然后您可以补充
答案 1 :(得分:0)
您需要使用:
class TestService(ServiceMap):
def __init__(self, url, connection, value=None):
super(TestService, self).__init__(value=value)
这将调用父类的__init__()
,在您的情况下ServiceMap
并创建所需的mro。
答案 2 :(得分:0)
public class StudioEnableEvent : PubSubEvent<bool>
{
}
的第一个参数是您希望获得父类的点。通常,它与您当前定义的类相同,因此您将获得当前正在定义的类的父级的super()
方法。在这种情况下,您要使用__init__
。有时,您将定义super(TestService, self)
的子类,而不是定义TestService
方法。这意味着将使用__init__
TestService
方法。由于__init__
明确使用了TestService
TestService
,您仍然会获得正确的父super()
方法。如果您使用__init__
,这可能很诱人,那么该行将进入子类的无限递归。
答案 3 :(得分:0)
在扩展超类中的方法时使用<TextView android:id="@+id/title" android:layout_width="wrap_content" android:layout_height="wrap_content" "/>
,即您希望运行超类的方法代码以及子类中的代码。
您的示例代码不正确:您需要致电
super
运行超类的__ init __方法,然后您可以继续初始化子类。
如果您没有扩展方法,则不需要进行super(TestService, self)__ init __ (value=value)
调用,只是不要在子类中定义方法,并且超类代码将运行。
如果要覆盖方法,请在子类中定义方法,但不要调用super
。
在Python3中,你不需要将参数传递给super
,你可以直接调用
super
(编辑反映Zondo的评论)