如何在Python中重新創建/重新生成一個對象2.7

Question

我正在尋找一種方法來在python中重新創建對象，因爲我希望對象在每個循環中都有一個默認屬性。

for case in all_case: 

    # I want an object to be newly created/reinstantiated in each loop 
    pda = PushDownAutomata() 
    print pda.evaluate(case, debug=False) 

    # I already added "del pda" but it does not work 

我該如何實現它？

Answer 1

請注意，類屬性與實例屬性不同。 例如：

class A(object): 

    a = None # this is a class attribute 

    def __init__(self, b): 
     self.b = b # b is an instance attribute 

Answer 2

該問題已通過以下代碼修復。我之前正在使用類變量 - 將其更改爲實例變量解決了問題：

# before (class variable) 
class PushDownAutomata(): 
    stack = [] 
    state = 'q1' 

# after (instance variable) 
class PushDownAutomata(): 
    def __init__(): 
     self.stack = [] 
     self.state = 'q1'