python学习记录（持续更新）--最最最基础的一部分（方法，异常处理，注释，类）

写在前面

本系列教程针对有一定编程经验的伙伴快速入门python基础，一些涉及开发的常识问题，本文并不涉及。

方法 function

def greet_user(name):
    print(f'Hi {name}!')
    print('Welcome aboard')


print('Start')
greet_user('jay')
print("Finish")

=>

Start
Hi jay!
Welcome aboard
Finish

传递参数

def greet_user(first_name,last_name):
    print(f'Hi {first_name} {last_name}!')
    print('Welcome aboard')


print('Start')
greet_user(last_name='chou',first_name='jay')
print("Finish")
=>

Start
Hi jay chou!
Welcome aboard
Finish

 异常处理

try:
    age= int(input('Age: '))
    print(age)
    print(1/age)
except ZeroDivisionError:
    print('Age cannot be 0')
except ValueError:
    print("Invalid value")

注释 

#这是注释

类

class Point:
    def __init__(self,x,y):
        self.x= x
        self.y = y



    def move(self):
        print("move")


    def draw(self):
        print("draw")


point1=Point(10,30)
point1.x=10
point1.y=20
print(point1.y)
point1.draw()

20
draw

#2

class Person:
    def __init__(self,name):
        self.name=name

    def talk(self):
        print(f"Im {self.name}")


p1=Person("JayChou")
p1.talk()
=>
Im JayChou

#继承

class Mammal:
    def walk(self):
        print("walk")


class Dog(Mammal):
    pass


class Cat(Mammal):
    pass


dog1 = Dog()
dog1.walk()