分配之前引用的局部變量「age」

Question

我最近開始學習python。並正在處理一個問題。

class Person: 
    age = 0 
    def __init__(self,initial_Age): 
     if initial_Age<0: 
      age=0 
      print("This person is not valid, setting age to 0.") 
     else: 
      age = initial_Age 

    def amIOld(self): 
     if(age<13): 
      print("You are young.") 
     elif(age>=13 and age<18): 
      print("You are a teenager.") 
     else: 
      print("You are old.") 
    def yearPasses(self): 
     age = age + 1 
T=int(input()) 
for i in range(0,T): 
age=int(input())   
p=Person(age) 
p.amIOld() 
for j in range(0,3): 
    p.yearPasses();   
p.amIOld(); 
print ("") 

我得到的錯誤顯示如下：

Traceback (most recent call last): 
File "solution.py", line 27, in <module> 
p.yearPasses();   
File "solution.py", line 19, in yearPasses 
age = age + 1 
UnboundLocalError: local variable 'age' referenced before assignment 

這種情況的輸入是這樣：

4(Number of test cases) 
-1 
10 
16 
18 

輸出必須是這樣的：

This person is not valid, setting age to 0. 
You are young. 
You are young. 

You are young. 
You are a teenager. 

You are a teenager. 
You are old. 

You are old. 
You are old. 

可以請你引導我w我做錯了什麼？由於

Answer 1

在Python中，你必須使用明確self訪問實例屬性：

class Person: 
    def __init__(self, initial_Age): 
     if initial_Age < 0: 
      self.age = 0 
      print("This person is not valid, setting age to 0.") 
     else: 
      self.age = initial_Age 

    def amIOld(self): 
     if self.age<13: 
      print("You are young.") 
     elif self.age>=13 and self.age<18: 
      print("You are a teenager.") 
     else: 
      print("You are old.") 

    def yearPasses(self): 
     self.age += 1