25 案例练习
25.1创建两个人的字典，存储在列表，遍历列表，输出列表
people_nums1 = {'name':'jetty','name1':'jack'} people_nums2 ={'name':'kitty','name1':'james'} peoples = [people_nums1,people_nums2] for i in peoples: print(i)
26.用户输入和while循环
ipt = input('你是小黄么？1(true) or 2(false)?') if ipt =='1': print('是本人') else: print('不是本人')
27 % //运算符
print(4 % 2) # 0 print(4 // 2) # 2
28 while运算符
count = 0 arr = [] while count < 20: for j in range(1, 100): if j % 11 == 0: count = count+1 arr.append(j) print(arr)
29 函数
# 简单求和 def num_sum(arr): result =0 for i in arr: result =result+i return result print(num_sum([1,2,3,4])) #10
30 函数默认值
def num_sum(arr=[1,2,3]): result =0 for i in arr: result =result+i return result print(num_sum()) #6
31 传递任意数量的实参
def make_prize(*top): return top print(make_prize(1)) print(make_prize(1,2,3)) print(make_prize(1,3,4,5)) print(make_prize(1,1,1,1,1)) # 返回 (1,) (1, 2, 3) (1, 3, 4, 5) (1, 1, 1, 1, 1)
32 导入函数
# 随机数 import random print(random.randint(1,19))
33 类
class Dog(): def __init__(self,name,age): self.name =name self.age = age def sit(self): print(self.name+''+self.age) dog = Dog('jeety',24) print(dog.name)
34 类 汽车里程表
class Car(): def __init__(self,make,model,year): self.make = make self.model = model self.year = year def getCarName(self): print(self.model) car = Car('audi','ad4',2016) print(car.make)
35 子类方法 __init__()
class Car(): def __init__(self,name): self.name = name class Elastic(Car): def __init__(self, name): super().__init__(name) myTesla = Elastic('tesla') print(myTesla.name)
36 class实例
class Car(): def __init__(self,make,name,color): self.make = make self.name = name self.color = color def getCarName(self): print('获取车的名字为'+self.name+'获取汽车的颜色'+self.color) class Batery(): def __init__(self,batery='60'): self.batery = batery def discribe_batery(self): print('This car has'+str(self.batery)+'batery') class Elatrity(Batery): def __init__(self, batery): super().__init__(batery) self.batery = Batery() elatrity = Elatrity('100') print(elatrity.discribe_batery())
37 文件和异常
f = open('file.txt',mode="w",encoding='utf-8') print(f) f.write('叫我詹躲躲\n') f.write('叫我詹躲躲1\n') f.close()
38 存储数据
将数据存入json文件
import json numbers = [1,2,23,3,4,5,6,7,87] filename = 'numbers.json' with open(filename,'w') as f_obj: json.dump(numbers,f_obj)
39 保存和读取用户生成的数据
import json username = input('存储输入的数据') filename = 'numbers.json' with open(filename,'w') as f_obj: json.dump(username,f_obj)
40 读取用户输入的信息
import json filename = 'numbers.json' with open(filename) as f_obj: username = json.load(f_obj) print('Welcome back',username)
41 输入和合并数据
import json filename = 'numbers.json' try: with open(filename) as f_obj: username = json.load(f_obj) except FileNotFoundError: username = input('存储输入的数据') with open(filename,'w') as f_obj: json.dump(username,f_obj) else: print('Welcome back',username)
42 封装成为一个函数
import json def get_username(): filename = 'numbers.json' try: with open(filename) as f_obj: username = json.load(f_obj) except FileNotFoundError: return None else: return username def get_greeting(): username = get_username() if username: print('Welcome back',username) else: username = input('存储输入的数据') filename = 'numbers.json' with open(filename,'w') as f_obj: json.dump(username,f_obj) print('Welcome back',username) get_greeting()
