Python 类垃圾邮件：numInstances=0 def\uuuu init\uuu（self）：

这给了我一个错误：

class Spam:
    numInstances = 0
    def __init__(self):
        Spam.numInstances = Spam.numInstances + 1
    def printNumInstances():
        print("Number of instances created: %s" % Spam.numInstances)

x = Spam()
x.printNumInstances()

我不明白为什么

我想它应该打印1。

您已经将printNumInstances声明为静态方法，但您将其作为实例方法调用

我想你想要垃圾邮件

---

虽然它应该是一个类方法，但如果我正确理解了代码，请参见：

您需要在“printNumInstances”方法中添加“self”

Traceback (most recent call last):                                                                                            
  File "main.py", line 9, in <module>                                                                                         
    x.printNumInstances()                                                                                                     
TypeError: printNumInstances() takes 0 positional arguments but 1 was given

见下文

def printNumInstances(self):
    .....

class Spam:
    numInstances = 0
    def __init__(self):
        Spam.numInstances = Spam.numInstances + 1
    def printNumInstances(self):
        print("Number of instances created: %s" % Spam.numInstances)

x = Spam()
x.printNumInstances()