Python基本语法（笔记）_from student import student是什么意思

1.列表

1. 一般名称为复数，用[]表示
2. 访问print（names[0]）
3. 修改 names[0]=’ name’
4. 添加 names.append(‘name’) 末尾
5. 插入 names.insert(-1,‘name’)
6. 删除 del names[0] #(语句)无法访问 names.remove(‘name’) #未知位置，第一个值 poped_name=names.pop(0) #（方法）默认末尾，继续使用
7. 排序 names.sort(reverse=True) #字母顺序 (反) sorted(names) #临时排序 【小写】
8. 倒着打印 names.reverse() #永久性
9. 遍历列表

 for name in names:
	 print(name)
print("thank you!)
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10.创建数字列表

numbers=list(range(2,11,3)) 
print(numbers)
numbers=[value**2 for value in range(1,4)]
print(numbers)
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11.切片 print(names[0:3]) a_names=names[:]#复制

12.元组(不可变值)

names=('a','b')  
print(names[0])
names=('c')
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13.if语句
if-elif-else

2.字典

1.键值对student_0={‘name’:‘liu’,‘age’:8}
2.访问 print(student_0[‘name’])
3.添加 student_0[‘sex’]=‘man’
4.修改 student_0[‘age’]=18
5.删除 del studnet_0[‘age’]
6.遍历

for key,value in student_0.items():
	print(key,value)
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for key in student_0.keys():
	print(key)
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for value in student_0.values():
	print(value)
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#按顺序
for key in sorted(student_0.keys()):
	print(key)
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#不重复
for value in set(student_0.values()):
	print(value)
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while 循环

函数

def names(*name)
	for name in names:
		print(name)
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def names(**name):
	student_names={}
	for key,value in name.items():
		student_names[key]=value
	return student_names

student_name=names(first_name='a',
									last_name='b')
print(student_name)
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{'first_name':'a','last_name':'b'}
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2.将函数储存在模块中
1.导入模块 import student(文件名，py形式)
2.导入函数 from student import student_0,student_1

#全部函数
from student import *
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3.as命名 import student as stu

from student import student_0 as stu_0
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类

class Car():
    
    def __init__(self,make,model,year):
        """初始化描述汽车的属性"""
        self.make=make
        self.model=model
        self.year=year
        self.odometer_reading=0
        
    def get_descriptive_name(self):
        """返回整洁的描述性信息""" 
        long_name = str(self.year) + ' ' + self.make + ' ' + self.model 
        return long_name.title()
    
    def read_odometer(self):
        """打印一条指出汽车里程的信息"""
        print("This car has"+str(self.odometer_reading)+"miles on it.")

    def update_odometer(self,mileage):
        """ 将里程表读数设置为指定的值 禁止将里程表读数往回调 """
        if mileage>=self.odometer_reading:
            self.odometer_reading=mileage
        else:
            print("you van't roll back an odometer!")


my_new_car=Car('audi','a4',2016)
print(my_new_car.get_descriptive_name())
my_new_car.read_odometer()

my_new_car.odometer_reading=22
my_new_car.read_odometer()

my_new_car.update_odometer(30)
my_new_car.read_odometer()
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继承

class ElectricCar(Car):
    
    """电动汽车的独特之处"""
    
    def __init__(self,make,model,year):
        """初始化父类的属性"""
        super().__init__(make,model,year)
        self.battery_size=50
        
    def describe_battery(self):
        """打印一条描述电瓶容量的消息"""
        
        print("This car has a "+ str(self.battery_size)+"-kwh battery.")

        
    def fill_gas_tank():
        """电动汽车没有邮箱"""
        print("This car doesn't need a gas tank!")
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将实例用作属性

class Car(): 
--snip-- 

class Battery(): 
 """一次模拟电动汽车电瓶的简单尝试""" 
 	
 	def __init__(self, battery_size=70):
 	 """初始化电瓶的属性""" 
 	 	self.battery_size = battery_size 
 	 
 	 def describe_battery(self): 
	 """打印一条描述电瓶容量的消息""" 
 		print("This car has a " + str(self.battery_size) + "-kWh battery.")

 class ElectricCar(Car):
  """电动汽车的独特之处""" 
  
  	def __init__(self, make, model, year): 
  	""" 初始化父类的属性，再初始化电动汽车特有的属性 """
  		
  		super().__init__(make, model, year) 
  		self.battery = Battery() 

my_tesla = ElectricCar('tesla', 'model s', 2016)
print(my_tesla.get_descriptive_name())
my_tesla.battery.describe_battery()
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