Python基础-TypeError:takes 2 positional arguments but 3 were given

时间:2023-03-08 22:48:20
Python基础-TypeError:takes 2 positional arguments but 3 were given

Error:

  今天写一段简单类定义python代码所遇到报错问题:TypeError: drive() takes 2 positional arguments but 3 were given

代码如下

  

class Car:
speed = 0
def drive(self,distance):
time = distance / self.speed
print(time) bike = Car()
bike.speed=60
bike.drive(60,80)

后经排查,才发现是类定义中 def drive(selef,distance) 方法中self参数得问题

现在让我们简单了解一下Python中self的基础信息:

self,表示创建的类实例本身,方法内部,就可以把各种属性绑定到self,因为self就指向创建的实例本身。在创建实例的时候,就不能传入空的参数了,必须传入与方法匹配的参数,但self不需要传,Python解释器会自己把实例变量传进去。

所以有两种解决方法

方法一:只传一个参数,如果你想传两个参数,那就看方法二

class Car:
speed = 0
def drive(self,distance):
time = distance / self.speed
print(time) bike = Car()
bike.speed=60
bike.drive(80)

方法二:

class Car:
speed = 0
def drive(self,distance,speed):
time = distance / speed
print(time)
bike = Car()
bike.drive(80,50)