派生类的python构造函数

Question

class baseClass():
  def __init__(self,mark,name):
    self.mark = mark
    self.name = name

class derivedClass(baseClass):

b1 = derivedClass(name='Jibin')
print b1.name

这是我最初的代码，运行良好。

(注意:我无权访问baseClass)

但后来我不得不将一个额外的属性rank传递给derivedClass。所以我这样编辑代码。

class baseClass():
  def __init__(self,mark,name):
    self.mark = mark
    self.name = name

class derivedClass(baseClass):
  def __init__(self,rank):
    self.rank = rank 

b1 = derivedClass(name='Jibin')
print b1.name

这导致了错误__init__() got an unexpected keyword argument 'name'

这是预期的，因为 derivedClass 的 __init__ 没有参数 name。

我不想在 derivedClass 的 __init__ 中添加额外的参数 name b'cos in real baseClass 有 10 个参数而不是 2(mark,name) & 如果我将所有参数都作为附加参数提供给 derivedClass 我将弄乱它的参数列表。

注意:我知道使用 baseClass.__init__(self) 或 super(derivedClass, self).__init__()

初始化 baseClass

Answer 1

也许你可以试试这样的东西

class BaseClass(object):
  def __init__(self, mark=None, name=None):   # you're using named parameters, declare them as named one.
    self.mark = mark
    self.name = name

class DerivedClass(BaseClass):   # don't forget to declare inheritance
  def __init__(self, rank=None, *args, **kwargs):    # in args, kwargs, there will be all parameters you don't care, but needed for baseClass
    super(DerivedClass, self).__init__(*args, **kwargs)
    self.rank = rank 

b1 = DerivedClass(name='Jibin')
print b1.name