class Person : population=0 def __init__(self,name): self.name=name print ('Initializing %s' % self.name) Person.population+=1 def sayHi(self): print ('hi,My name is %s.' % self.name) def howMany(self): if Person.population==1: print ('I am the current population .') else: print ('We have %d persons here ' % Person.population) swaroop=Person('Swaroop') swaroop.sayHi() swaroop.howMany() kalam=Person('Abdul kalam') kalam.sayHi() kalam.howMany() swaroop.sayHi() swaroop.howMany()
如上面Python代码,是学习python类时遇到的一个小例子。但是在运行时会报错:
Traceback (most recent call last):
File “E:/PythonStudy/objvar.py”, line 18, in <module>
swaroop=Person(‘Swaroop’)
TypeError: object() takes no parameters
经过查阅资料才知道,是构造函数里的下划线的问题,
__init__(self,name)这个构造函数的左右下划线都是两个,我只用了一个,导致错误