为什么这段代码不起作用？(蟒蛇)

Question

class MyClass:

     def __init__(self):
         pass

     val = ""

     def getval(self):
         # code to get val 
         # ... and at the end:
         self.val = "bla bla"

     self.getval()
     print val

现在在这一点上它说没有找到名称self.如果我只尝试getval()(没有自己的前缀),那么它表示没有getval方法接受0个参数.请有人能解释一下为什么这段代码不起作用？

Answer 1

这是一个更有意义的例子:

class MyClass:
     def __init__(self):
         pass

     # this is a class variable
     val = ""

     def getval(self):
         # code to get val 
         # ... and at the end:
         self.val = "bla bla"
         return self.val

# make a instance of the class
x = MyClass()
print x.getval()

# MyClass.val is a different class variable
print MyClass.val

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