這是爲什麼導致遞歸錯誤

Question

我試了一下在這裏推薦https://stackoverflow.com/a/41112823/5618523但我仍然有問題

class AppendiveDict(c.OrderedDict): 
    def __init__(self,func,*args): 
     self.func = func 
     c.OrderedDict.__init__(self,args) 
    def __setitem__(self, key, value,): 
     if key in self: 
      self[key] = self.func(self[key]) 
     else: 
      c.OrderedDict.__setitem__(self,key,value) 
a = AppendiveDict((lambda y: y + "sdf"),("a","b"),("c","d"),("e","f"),("a","b")) 
a 

此類的一點是，它是假設在字典的時候就已經申請項的功能它會重現這個項目。

RecursionError       Traceback (most recent call last) 
<ipython-input-15-b4bd349c86bf> in <module>() 
    11   else: 
    12    c.OrderedDict.__setitem__(self,key,value) 
---> 13 a = AppendiveDict((lambda y: y + "sdf"),("a","b"),("c","d"),("e","f"),("a","b")) 
    14 a 

<ipython-input-15-b4bd349c86bf> in __init__(self, func, *args) 
     5  def __init__(self,func,*args): 
     6   self.func = func 
----> 7   c.OrderedDict.__init__(self,args) 
     8  def __setitem__(self, key, value,): 
     9   if key in self: 

<ipython-input-15-b4bd349c86bf> in __setitem__(self, key, value) 
     8  def __setitem__(self, key, value,): 
     9   if key in self: 
---> 10    self[key] = self.func(self[key]) 
    11   else: 
    12    c.OrderedDict.__setitem__(self,key,value) 

數3只是重複 。如果我c.OrderedDict後放self.func。 init（self，args）它會導致屬性錯誤，說self.func不存在。

Answer 1

因爲self[key]電話__setitem__再次，你可以嘗試：

def __setitem__(self, key, value,): 
     if key in self: 
      c.OrderedDict.__setitem__(self, key, self.func(value)) 

編輯： 雖然重新閱讀，你打算修改當前設定值：

def __setitem__(self, key, value): 
    if key in self: 
     c.OrderedDict.__setitem__(self, key, self.func(self[key])) 

工作過，如果是你以後的樣子。