day2

重点：

• 多个数据储存到单变量，分成列表:[...]、元组(...)、字典{...}。其中元组只读不能修改，类似于C++的enum；字段需要在里面自定义索引{"index1":'Content'}.
• python中变量复制的关系不同于C++，C++中变量复制对每个都分配内存（除了设定指针），但python会节省内存设定指针.

tuple:

#元组,不能修改，又叫只读列表
names=('a1','a2','a3','a4')
#1、count()：查找元素在tuple中出现的次数。
#2.index()：查找元素的第一个索引值。
print(names.count('a1'))
print(names.index('a4'))

variance and copy:

import copy
#浅copy本质上是引用，只能第一层复制，列表中的列表只复制指针

var1=['name',['a',100]]
#引用的三种方式
p1=copy.copy(var1)#string会新建立内存，但是列表只复制指针
p2=var1[:]        #string会新建立内存，但是列表只复制指针
p3=list(var1)     #string会新建立内存，但是列表只复制指针
print(p1,p2,p3)

p4=p1 #若直接用=，则建立指针

p1[0]='abc' #只修改p1，不影响p2,p3，但影响p4
p2[0]='def' #只修改p2，不影响p1,p3
p3[1][0]="ABC" #指向的内容修改，影响其他
print(p1,p2,p3,p4)

 

import:

import sys
print(sys.path)  # 打印环境变量
print(sys.argv)  # 打印当前脚本路径

import os
cmd_res = os.system("dir")  # 执行win命令，不保存结果
print("-->", cmd_res)
cmd_res = os.popen("dir").read()  # 保存结果
print("-->", cmd_res)
# os.mkdir("test")  #在当前脚本所在目录创建目录

 

data type:

#python中数据类型：int,float,complex
print(type(10*24))
print(type(23.123465789))
print(type(5+4j))  #python中虚数用j表示，不同于数学用i表示.

 

三元运算：

#三元运算
a,b,c=100,200,300
d=a if a>b else c
print(d)
e= 100 if 200>1000 else 200
print(e)

 

16进制，byte与str:

#16进制表示法
'''
后缀：H
前缀：0x
'''

#python3中 byte字节与str字符串是区分的，两者可以转换
print('€20'.encode('utf-8'))                #.encode():str转二进制byte
print(b'\xe2\x82\xac20'.decode('utf-8'))    #.decode():byte转str

msg = '我爱北京天安门'
print(msg)
print(msg.encode('utf-8'))
print(msg.encode('utf-8').decode('utf-8'))

 

列表的一些操作：

# Author:Zhang Yuan

names = 'A1 A2 A3 A4'
print(names)

names=['A1','A2','A3','A4']
print(names[0],names[2])
print(names[1]+' '+names[2])
#切片(顾头不顾尾)
print(names[1:3])
print(names[0:2])
print(names[3:])  #取后面的
print(names[-2:])

names.append("A5") #追加一个到最后
print(names)
names.insert(1,"A1.5") #插入到指定位置
print(names)
names[1]='A1.55' #修改
print(names)

#delete
names.remove("A2")
print(names)
del names[1]
print(names)
names.pop(2)
print(names)

#查找元素
print(names.index("A5"))
print(names[names.index("A5")])

#列表有相同元素
names.append("A3") #追加一个到最后
print(names)
print(names.count("A3")) #返回列表中多少个指定元素


names.reverse() #列表翻转
print(names)

names.sort() #排序列表

names2=[1,2,3,4]
names.extend(names2) #合并列表name2到name1末尾
#del names2 #删除列表name2

#列表中可以再追加列表，追加列表本质是追加指针
names.append(["B1","B2"])

names2 = names.copy() #普通copy只能复制第一层
import copy
names3=copy.deepcopy(names) #深度copy相当于重新建立内存

names[-1].append("B3") #指针指向的列表追加的数据，所以下面names,names2两个变量都显示变化
print(names,names2,names3)

#不同于c++数组，python内存和变量的关系与c++不同！！！
a=[1,2,3] #分配内存，a指向数据
b=a       #b也指向a指向的数据
c=a.copy()#复制，新增加内存储存数据
a[-1]=66  #通过a修改内存数据
print(a,b,c)  #所以b变化,c不变
a[0]=66   #通过a修改内存数据
print(a,b,c)  #所以b变化,c不变
a=[1,2,3] #a重新赋值，相当于重新分配内存，但是b指向的内存依然不变
print(a,b,c)  #所以b不变,c不变

#列表的有步长的切片
print(names,names[0::2]) #从开始到末尾，包括末尾
print(names,names[::2])  #0可以省略

#列表的循环
for i in names:
    print(i)


#清空列表
#names.clear()
#print(names)

 

string的一些操作：

# Author:Zhang Yuan

name="my \tname is {name} and I am {year}"

print(name.capitalize())
print(name.count("a"))
print(name.center(50,"-"))
print(name.endswith("an"))
print(name.expandtabs(tabsize=30))
print(name[name.find("name"):])
print(name.format(name='ZhangYuan',year='30'))
print(name.format_map( {"name":"ZhanXiang","year":33} ))
print("AB123".isalnum())
print("AB123".isalpha())
print("1A".isdecimal())    #判断是否为十进制
print('A1'.isidentifier()) #判断是否为合法的标识符
print("33".isnumeric())
print("   ".isspace())
print("My Name Is".istitle())
print("My Name Is".isprintable()) #tty file,drive file
print("MY NAME".isupper())
print("+".join(["1","2","a"]))
print(name.ljust(50,'*'))
print(name.rjust(50,'*'))
print("ABCDE,ASF".lower())
print("ABCDE,ASF,asdfadsfg".upper())
print('  \nabcdasdf'.lstrip()) #从左边开始去除空格和回车
print('asdf   \n   '.rstrip())
print(' \n   asdf   \n   '.strip())
print("abcde".translate(str.maketrans("abcefg","123456")))
print('alex li'.replace("1",'L',1))
print('alex li'.rfind("l"))
print("123.132.321".split("."))
print('1+2\n+3+4'.splitlines())
print("Acd".swapcase())
print("fdsa erf df".title())
print('asdfdsa'.zfill(20))

 

购物车（自己版本）：

# Author:Zhang Yuan
goods1=['G1',256]
goods2=['G2',300]
goods3=['G3',400]
goods4=['G4',123]
goods5=['G5',56]
goods6=['G6',321]

wallet=1000
ShoppingCart=[]
print('your wallet have $', wallet)
while (wallet > 56):
    buy=input("what do you want to buy? G1-G6 or Stop")
    if buy==goods1[0]:
        goods=goods1
        if wallet>goods[1]:
            ShoppingCart.append(goods1)
            wallet=wallet-goods[1]
            print("your shopping carts are:",ShoppingCart,' your wallet have',wallet)
        else:
            print("your need$", goods[1], 'but your have $', wallet)
    elif buy==goods2[0]:
        goods=goods2
        if wallet>goods[1]:
            ShoppingCart.append(goods2)
            wallet=wallet-goods[1]
            print("your shopping carts are:",ShoppingCart,' your wallet have',wallet)
        else:
            print("your need$", goods[1], 'but your have $', wallet)
    elif buy==goods3[0]:
        goods=goods3
        if wallet>goods[1]:
            ShoppingCart.append(goods3)
            wallet=wallet-goods[1]
            print("your shopping carts are:",ShoppingCart,' your wallet have',wallet)
        else:
            print("your need$", goods[1], 'but your have $', wallet)
    elif buy==goods4[0]:
        goods=goods4
        if wallet>goods[1]:
            ShoppingCart.append(goods4)
            wallet=wallet-goods[1]
            print("your shopping carts are:",ShoppingCart,' your wallet have',wallet)
        else:
            print("your need$", goods[1], 'but your have $', wallet)
    elif buy==goods5[0]:
        goods=goods5
        if wallet>goods[1]:
            ShoppingCart.append(goods5)
            wallet=wallet-goods[1]
            print("your shopping carts are:",ShoppingCart,' your wallet have',wallet)
        else:
            print("your need$", goods[1], 'but your have $', wallet)
    elif buy==goods6[0]:
        goods=goods6
        if wallet>goods[1]:
            ShoppingCart.append(goods6)
            wallet=wallet-goods[1]
            print("your shopping carts are:",ShoppingCart,' your wallet have',wallet)
        else:
            print("your need$",goods[1],'but your have $',wallet)
    elif buy=='Stop':
        print('your stop buy by yourself')
        print("your shopping carts are:", ShoppingCart, ' your wallet have', wallet)
        break
else:
    print("your have spend most of your money, your can't buy any more")

 

购物车（其他版本）：

# Author:Zhang Yuan

product_list=[
    ('Iphone',5800),
    ('Mac Pro',9800),
    ('Watch',10600),
    ('Coffee',30),
    ('Book',120)
]
shopping_list=[]
salary = input('Input your salary:')
#判断输入的字符串是否为数字
if salary.isdigit()==True:
    salary=int(salary)
    while True:
        #普通的索引方式
        '''
        for item in product_list:
            print(product_list.index(item),item)
        '''
        #enumerate相当于枚举式的索引，单独一个变量中存储“序号和内容”
        '''
        for item in enumerate(product_list):
            print(item)
        '''
        #两个变量分别存储：index-序号、item-内容
        for index,item in enumerate(product_list):
            print(index,item)
        user_choice=input('what do you want to buy?  or q?')
        if user_choice.isdigit()==True:
            user_choice=int(user_choice)
            #len()返回列表的长度
            if user_choice<len(product_list) and user_choice>=0:
                p_item=product_list[user_choice]
                if p_item[1]<=salary:
                    shopping_list.append(p_item)
                    salary-=p_item[1]
                    print('Added %s into shopping cart,your current balance is \033[31;1m%s\033[0m' %(p_item,salary))
                else:
                    print('\033[41;1mYour salary only have %s\033[0m'%salary)
            else:
                print('product code [%s] is not exist'%user_choice)
        elif user_choice=="q":
            print('------shopping list---')
            for p in shopping_list:
                print(p)
            print('your current balance:',salary)
            exit()
        else:
            print('invalid input')

 

字典的使用：

# Author:Zhang Yuan
#key-value
info={
    'stu1101':'A1',
    'stu1102':'A2',
    'stu1103':'A3',
}
info2={
    'stu1101':'B1',
    '123':'456'
}
info.update(info2)#相同索引覆盖，新索引添加
print(info)
print(info['stu1101'])
print(info.get('stu1105')) #这种方式不会出错
print(info.get('stu1102'))

info['stu1101']='B1'
info['stu1104']='Add'
print(info)

#delete
del info['stu1101']
info.pop('stu1104')
print(info)

#dictionary嵌套
av_catalog={
    "Euro":{
        "index1":["www.youporn.com","Free,General Quality"],
        "index2":["www.pornhub.com","Free,High Quality"],
        "index3":["letmedothistoyou.com","self"],
        "index4":["x-art.com","Very High Quality,Not Free"]
    },
    "Japan":{
        "index1":["tokyo-hot"]
    },
    "China":{
        "index1":["1024"]
    }
}
av_catalog["China"]["index1"][0]='ABCDE'
print(av_catalog.values())
print(av_catalog["Euro"].keys())

av_catalog.setdefault("TaiWan",{"index1":["www.baidu.com"]}) #setdefault()当没有时创建，当有时不变
av_catalog.setdefault("China",{"index1":["www.baidu.com"]}) #setdefault()当没有时创建，当有时不变
print(av_catalog)

print(info)
print(info.items())

c=dict.fromkeys([6,7,8],[1,{"index1":"abc"},444])#共同指向一个地址
print(c)
c[7][1]['index1']='def'#修改一个则全部修改
print(c)

for i in av_catalog:
    print(i,av_catalog[i])

#字典转列表，如果数据量大要很久
for k,v in av_catalog.items():
    print(k,v)

 

三级菜单：

# Author:Zhang Yuan
data={
    "AnHui":{
        "HeFei":{
            "FeiXi":"肥西",
            "FeiDong":"肥东"
        },
        "LuAn":{
            "YuAn":"裕安",
            "JinAn":"金安"
        }
    },
    "ShangHai":{
        "PuDong":{
            "LuJiaZui":"陆家嘴"
        },
        "XuHui":{
            "XuJiaHui":"徐家汇"
        }
    },
}
print(data["AnHui"]["LuAn"]["YuAn"])

while True:
    for i in data:
        print(i)

    choice=input("Choice to get in 1:")
    if choice in data:
        while True:
            for j in data[choice]:
                print("\t",j)

            choice2=input("Choice to get in 2:")
            if choice2 in data[choice]:
                while True:
                    for k in data[choice][choice2]:
                        print("\t\t",k)

                    choice3=input("Choice to get in 3:")
                    if choice3 in data[choice][choice2]:
                        for l in data[choice][choice2][choice3]:
                            print("\t\t\t", l)
                        print("last get in,input b get out")
                    elif choice3=="b":
                        break
            elif choice2=="b":
                break
    elif choice=="b":
        break