一、列表
列表是我们最以后最常用的数据类型之一，通过列表可以对数据实现最方便的存储、修改等操作
定义列表
names = ["ZhangYang", "Guyun", "Xiangpeng", "XuLiangChen"]
根据下标取值，下标从0开始
print(names)print(names[0], names[2])运行结果：['ZhangYang', 'Guyun', 'Xiangpeng', 'XuLiangChen']ZhangYang Xiangpeng
切片取值
print(names[1:3]) # 切片，取下标1和下标3之间的值，包括1但不包括3print(names[3]) # 切片，取下标3的值print(names[-2]) # 切片，取倒数第2个值print(names[-2:]) # 切片，取列表最后2个值print(names[0:3]) # 切片，取列表前3个值print(names[:3]) # 切片，前边是0的，可以忽略运行结果['Guyun', 'Xiangpeng']XuLiangChenXiangpeng['Xiangpeng', 'XuLiangChen']['ZhangYang', 'Guyun', 'Xiangpeng']['ZhangYang', 'Guyun', 'Xiangpeng']
列表追加
names = ["ZhangYang", "Guyun", "Xiangpeng", "XuLiangChen"]names.append("Leihaidong") # 最后追加print(names)运行结果['ZhangYang', 'Guyun', 'Xiangpeng', 'XuLiangChen', 'Leihaidong']指定下标插入
names = ["ZhangYang", "Guyun", "Xiangpeng", "XuLiangChen"]names.insert(1, "Chenronghua") # 指定位置插入names.insert(3, "Xinzhiyu")print(names)运行结果['ZhangYang', 'Chenronghua', 'Guyun', 'Xinzhiyu', 'Xiangpeng', 'XuLiangChen']
替换列表值
names=['ZhangYang', 'Chenronghua', 'Guyun', 'Xinzhiyu', 'Xiangpeng', 'XuLiangChen']names[2] = "Xiedi" #指定下标替换运行结果['ZhangYang', 'Chenronghua', 'Xiedi', 'Xinzhiyu', 'Xiangpeng', 'XuLiangChen']
删除列表值
names=['ZhangYang', 'Chenronghua', 'Guyun', 'Xinzhiyu', 'Xiangpeng', 'XuLiangChen']names.remove("Chenronghua") #删除指定的内容print(names)运行结果['ZhangYang', 'Guyun', 'Xinzhiyu', 'Xiangpeng', 'XuLiangChen']names=['ZhangYang', 'Chenronghua', 'Guyun', 'Xinzhiyu', 'Xiangpeng', 'XuLiangChen']del names[1] #根据下标删除print(names)运行结果['ZhangYang', 'Guyun', 'Xinzhiyu', 'Xiangpeng', 'XuLiangChen']
names=['ZhangYang', 'Chenronghua', 'Guyun', 'Xinzhiyu', 'Xiangpeng', 'XuLiangChen']names.pop(1) #删除最后一个print(names)运行结果['ZhangYang', 'Guyun', 'Xinzhiyu', 'Xiangpeng', 'XuLiangChen']
查找元素位置
names=['ZhangYang', 'Chenronghua', 'Xiedi', 'Xinzhiyu', 'Xiangpeng', 'XuLiangChen']print(names.index('Xiedi'))运行结果：2统计重复的元素个数
names=['ZhangYang', 'Chenronghua', 'Xiedi', 'Xinzhiyu','Chenronghua', 'Xiangpeng', 'XuLiangChen']print(names.count('Chenronghua'))运行结果：2反转列表
names=['ZhangYang', 'Chenronghua', 'Xiedi', 'Xinzhiyu','Chenronghua', 'Xiangpeng', 'XuLiangChen']print(names)names.reverse()print(names)运行结果：['ZhangYang', 'Chenronghua', 'Xiedi', 'Xinzhiyu', 'Chenronghua', 'Xiangpeng', 'XuLiangChen']['XuLiangChen', 'Xiangpeng', 'Chenronghua', 'Xinzhiyu', 'Xiedi', 'Chenronghua', 'ZhangYang']
列表排序(默认按照ASCII码排序)：
names = ["4ZhangYang", "#!Guyun", "Xiangpeng","Chenronghua", "XuLiangChen"]names.sort()print(names)运行结果：['#!Guyun', '4ZhangYang', 'Chenronghua', 'Xiangpeng', 'XuLiangChen']
列表扩展
names=['ZhangYang', 'Chenronghua', 'Xiedi', 'Xinzhiyu','Chenronghua', 'Xiangpeng', 'XuLiangChen']names2=[1, 2, 3, 4]names.extend(names2)print(names)运行结果：['ZhangYang', 'Chenronghua', 'Xiedi', 'Xinzhiyu', 'Chenronghua', 'Xiangpeng', 'XuLiangChen', 1, 2, 3, 4]
删除列表
names2 = [1, 2, 3, 4]del names2print(names2)运行结果：Traceback (most recent call last): File "/Users/erick/PycharmProjects/oldboy_python/day2/names.py", line 45, in <module> print(names2)NameError: name 'names2' is not defined
浅copy列表(只拷贝列表第一层的内存地址，当原列表第二层的元素发生改变时，新列表会跟着改变)
names = ["4ZhangYang", "#!Guyun", "xXiangpeng", ["alex", "jack"], "Chenronghua", "XuLiangChen"]names2 = names.copy()print(names)print(names2)names[2] = "向鹏"print(names)print(names2)names[3][0] = "ALEXANDER"print(names)print(names2)运行结果['4ZhangYang', '#!Guyun', 'xXiangpeng', ['alex', 'jack'], 'Chenronghua', 'XuLiangChen']['4ZhangYang', '#!Guyun', 'xXiangpeng', ['alex', 'jack'], 'Chenronghua', 'XuLiangChen']['4ZhangYang', '#!Guyun', '向鹏', ['alex', 'jack'], 'Chenronghua', 'XuLiangChen']['4ZhangYang', '#!Guyun', 'xXiangpeng', ['alex', 'jack'], 'Chenronghua', 'XuLiangChen']['4ZhangYang', '#!Guyun', '向鹏', ['ALEXANDER', 'jack'], 'Chenronghua', 'XuLiangChen']['4ZhangYang', '#!Guyun', 'xXiangpeng', ['ALEXANDER', 'jack'], 'Chenronghua', 'XuLiangChen']
深度copy(完全克隆)
import copynames = ["4ZhangYang", "#!Guyun", "xXiangpeng", ["alex", "jack"], "Chenronghua", "XuLiangChen"]# names2 = names.copy()names2 = copy.deepcopy(names)print(names)print(names2)names[2] = "向鹏"print(names)print(names2)names[3][0] = "ALEXANDER"print(names)print(names2)运行结果：['4ZhangYang', '#!Guyun', 'xXiangpeng', ['alex', 'jack'], 'Chenronghua', 'XuLiangChen']['4ZhangYang', '#!Guyun', 'xXiangpeng', ['alex', 'jack'], 'Chenronghua', 'XuLiangChen']['4ZhangYang', '#!Guyun', '向鹏', ['alex', 'jack'], 'Chenronghua', 'XuLiangChen']['4ZhangYang', '#!Guyun', 'xXiangpeng', ['alex', 'jack'], 'Chenronghua', 'XuLiangChen']['4ZhangYang', '#!Guyun', '向鹏', ['ALEXANDER', 'jack'], 'Chenronghua', 'XuLiangChen']['4ZhangYang', '#!Guyun', 'xXiangpeng', ['alex', 'jack'], 'Chenronghua', 'XuLiangChen']浅copy三种方法person=['name',['a',100]]p1=copy.copy(person)p2=person[:]p3=list(person)
列表循环
names = ["4ZhangYang", "#!Guyun", "xXiangpeng", ["alex", "jack"], "Chenronghua", "XuLiangChen"]for i in names: print(i)运行结果：4ZhangYang#!GuyunxXiangpeng['alex', 'jack']ChenronghuaXuLiangChen
二、元组
元组其实跟列表差不多，也是存一组数，只不是它一旦创建，便不能再修改，所以又叫只读列表
语法
names = ("alex","jack","eric")
它只有2个方法，一个是count,一个是index
三、程序练习
购物车程序
需求：
启动程序后，让用户输入工资，然后打印商品列表
允许用户根据商品编号购买商品
用户选择商品后，检测余额是否够，够就直接扣款，不够就提醒
可随时退出，退出时，打印已购商品和余额
product_list = [ ('Iphone', 5800), ('Mac Pro', 9800), ('Bike', 800), ('Watch', 10600), ('Coffee', 31), ('Alex Python', 120)]shopping_list = []salary = input("Input your salary:")if salary.isdigit(): salary = int(salary) while True: for index,item in enumerate(product_list): #print(product_list.index(item),item) print(index,item) user_choice = input("选择要买嘛？>>>:") if user_choice.isdigit(): user_choice = int(user_choice) if user_choice < len(product_list) and user_choice >= 0: p_item = product_list[user_choice] if p_item[1] <= salary: # 买的起 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;1m你的余额只剩[%s]啦，还买个毛线\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("your input error!")四、字符串操作
name = "my name is alex"print(name.capitalize()) # 首字母大写print(name.count("a")) # 统计指定字符的个数print(name.center(50,"-")) # 打印50个字符，不够的用"-"补充，name字符串居中print(name.endswith("ex")) # 判断字符串以什么结尾，匹配为True,不匹配为Falsename = "my \tname is alex"print(name.expandtabs(tabsize=30)) # 将\t转换成多长的空格print(name.find("name")) # 查找字符串位置print(name[name.find("name"):9]) # 字符串切片name = "my name is {name} and i am {year} old!"print(name.format(name="alex", year=23)) # 传递参数内容print(name.format_map({"name": "alex", "year": 23})) # 用字典的方式传递参数print("abc123".isalnum()) # 阿拉伯数字和阿拉伯英文字符,英文字符以及0-9数字print("abA".isalpha()) # 是否为阿拉伯英文字符print("10".isdecimal()) # 是否为十进制print("1".isdigit()) # 是否为整数print("addd_d".isidentifier()) # 是否为合法的标志符即变量名print("aa".islower()) # 是否为小写print("34234".isnumeric()) # 是否都为纯数字print("My Name Is ".istitle()) # 判断是否为title，即每单词首字母大写print("My Name Is ".isprintable()) # 判断能否打印,当是tty file或者drive fileprint("My Name Is ".isupper()) # 判断是否全为大写print("+".join(['1', '2', '3'])) # join成字符串print(name.ljust(50, "*")) # 左对齐，长度50个字符，并用*补齐print(name.rjust(50, "-")) # 右对齐，长度50个字符，并用-补齐print("Alex".lower()) # 把大写变成小写print("Alex".upper()) # 把小写变成大写print("\n Alex".lstrip()) # 去除左侧的空格或回车print("Alex \n".rstrip()) # 去除右侧的空格或回车print("\n Alex \n".strip()) # 去除两侧的空格或回车p = str.maketrans("abcdef", "123456") # 字符对应替换print("alex li".translate(p))print("alex li".replace('l', 'L')) # 替换指定字符print("alex li".replace('l', 'L', 1)) # 替换1次print("alex li".rfind('l')) # 从左往右查找，返回最右侧的匹配字符的下标print("al ex li".split()) # 切割，默认按照空格print("al ex li".split('l')) # 按照字符"l"切割print("al \nex li".splitlines()) # 按照换行符\n切割print("Alex Li".swapcase()) # 大写变小写，小写变大写print("alex li".title()) # 变成title即每个单词的首字母大写print("alex li".zfill(50)) # 长度50，不够用0左填充运行结果：My name is alex2-----------------my name is alex------------------Truemy name is alex4name my name is alex and i am 23 old!my name is alex and i am 23 old!TrueTrueTrueTrueTrueTrueTrueTrueTrueFalse1+2+3my name is {name} and i am {year} old!************------------my name is {name} and i am {year} old!alexALEXAlexAlexAlex1l5x liaLex LiaLex li5['al', 'ex', 'li']['a', ' ex ', 'i']['al ', 'ex li']aLEX lIAlex Li0000000000000000000000000000000000000000000alex li五、字典
字典一种key - value 的数据类型，使用就像我们上学用的字典，通过笔划、字母来查对应页的详细内容。
修改以及增加
info = { 'stu1101': "TengLan Wu", 'stu1102': "LongZe Luola", 'stu1103': "XiaoZe Maliya",}print(info)print(info['stu1101'])info["stu1101"] = "武藤兰" # 修改print(info)info["stu1104"] = "Cangjingkong" # 增加print(info)运行结果：{'stu1101': 'TengLan Wu', 'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya'}TengLan Wu{'stu1101': '武藤兰', 'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya'}{'stu1101': '武藤兰', 'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya', 'stu1104': 'Cangjingkong'}删除
info = { 'stu1101': "TengLan Wu", 'stu1102': "LongZe Luola", 'stu1103': "XiaoZe Maliya", 'stu1104': 'Cangjingkong',}# del# del info # 删除字典del info['stu1101'] # 删除元素print(info)info.pop("stu1102") # 删除元素print(info)info.popitem() # 随机删除一个print(info)运行结果：{'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya', 'stu1104': 'Cangjingkong'}{'stu1103': 'XiaoZe Maliya', 'stu1104': 'Cangjingkong'}{'stu1103': 'XiaoZe Maliya'}查找
info = { 'stu1101': "TengLan Wu", 'stu1102': "LongZe Luola", 'stu1103': "XiaoZe Maliya",}# 查找print(info.get('stu1103'))运行结果：XiaoZe Maliya多级字典嵌套
av_catalog = { "欧美":{ "www.youporn.com": ["很多免费的,世界最大的","质量一般"], "www.pornhub.com": ["很多免费的,也很大","质量比yourporn高点"], "letmedothistoyou.com": ["多是自拍,高质量图片很多","资源不多,更新慢"], "x-art.com":["质量很高,真的很高","全部收费,屌比请绕过"] }, "日韩":{ "tokyo-hot":["质量怎样不清楚,个人已经不喜欢日韩范了","听说是收费的"] }, "大陆":{ "1024":["全部免费,真好,好人一生平安","服务器在国外,慢"] }}av_catalog["大陆"]["1024"][1] = "可以在国内做镜像"print(av_catalog["大陆"]["1024"])运行结果：['全部免费,真好,好人一生平安', '可以在国内做镜像']打印keys和values
info = { 'stu1101': "TengLan Wu", 'stu1102': "LongZe Luola", 'stu1103': "XiaoZe Maliya",}print(info.values()) # 打印key值print(info.keys()) # 打印key运行结果：dict_values(['TengLan Wu', 'LongZe Luola', 'XiaoZe Maliya'])dict_keys(['stu1101', 'stu1102', 'stu1103'])setdefault
av_catalog = { "欧美":{ "www.youporn.com": ["很多免费的,世界最大的","质量一般"], "www.pornhub.com": ["很多免费的,也很大","质量比yourporn高点"], "letmedothistoyou.com": ["多是自拍,高质量图片很多","资源不多,更新慢"], "x-art.com":["质量很高,真的很高","全部收费,屌比请绕过"] }, "日韩":{ "tokyo-hot":["质量怎样不清楚,个人已经不喜欢日韩范了","听说是收费的"] }, "大陆":{ "1024":["全部免费,真好,好人一生平安","服务器在国外,慢"] }print(av_catalog.setdefault("台湾", {"www.baidu.com": [1, 2]})) # 如果能取到就返回这个值，取不到就创建新的print(av_catalog)print(av_catalog.setdefault("大陆", {"www.baidu.com": [1, 2]}))print(av_catalog)运行结果：{'www.baidu.com': [1, 2]}{'欧美': {'www.youporn.com': ['很多免费的,世界最大的', '质量一般'], 'www.pornhub.com': ['很多免费的,也很大', '质量比yourporn高点'], 'letmedothistoyou.com': ['多是自拍,高质量图片很多', '资源不多,更新慢'], 'x-art.com': ['质量很高,真的很高', '全部收费,屌比请绕过']}, '日韩': {'tokyo-hot': ['质量怎样不清楚,个人已经不喜欢日韩范了', '听说是收费的']}, '大陆': {'1024': ['全部免费,真好,好人一生平安', '服务器在国外,慢']}, '台湾': {'www.baidu.com': [1, 2]}}{'1024': ['全部免费,真好,好人一生平安', '服务器在国外,慢']}{'欧美': {'www.youporn.com': ['很多免费的,世界最大的', '质量一般'], 'www.pornhub.com': ['很多免费的,也很大', '质量比yourporn高点'], 'letmedothistoyou.com': ['多是自拍,高质量图片很多', '资源不多,更新慢'], 'x-art.com': ['质量很高,真的很高', '全部收费,屌比请绕过']}, '日韩': {'tokyo-hot': ['质量怎样不清楚,个人已经不喜欢日韩范了', '听说是收费的']}, '大陆': {'1024': ['全部免费,真好,好人一生平安', '服务器在国外,慢']}, '台湾': {'www.baidu.com': [1, 2]}}update
info = { 'stu1101': "TengLan Wu", 'stu1102': "LongZe Luola", 'stu1103': "XiaoZe Maliya",}b = { 'stu1101': "Alex", 1: 3, 2: 5}info.update(b) # 两个字典合并，有交叉就更新，无交叉就创建print(info)运行结果：{'stu1101': 'Alex', 'stu1102': 'LongZe Luola', 'stu1103': 'XiaoZe Maliya', 1: 3, 2: 5}items
info = { 'stu1101': "TengLan Wu", 'stu1102': "LongZe Luola", 'stu1103': "XiaoZe Maliya",}print(info.items()) # 将字典转换为列表运行结果：dict_items([('stu1101', 'TengLan Wu'), ('stu1102', 'LongZe Luola'), ('stu1103', 'XiaoZe Maliya')])fromkeys
c = dict.fromkeys([6,7,8],"test") # 初始化列表，参数列表为key，"test" 为默认key值print(c)运行结果：{6: 'test', 7: 'test', 8: 'test'}踩过的坑d = dict.fromkeys([6,7,8],[1,{"name":"alex"},444]) # 注意多层，引用的是内存地址print(d)d[7][1]["name"] = "Jcak chen"print(d)运行结果：{6: [1, {'name': 'alex'}, 444], 7: [1, {'name': 'alex'}, 444], 8: [1, {'name': 'alex'}, 444]}{6: [1, {'name': 'Jcak chen'}, 444], 7: [1, {'name': 'Jcak chen'}, 444], 8: [1, {'name': 'Jcak chen'}, 444]}循环字典
info = { 'stu1101': "TengLan Wu", 'stu1102': "LongZe Luola", 'stu1103': "XiaoZe Maliya",}for i in info: # 更为高效，建议用这种 print(i,info[i])for k,v in info.items(): # 先将字典转换为列表 print(k,v)六、三级菜单
实现：三级菜单打印，b返回上一级，q退出程序
data = { "北京": { "昌平":{ "沙河":["oldboy", "test"], "天通苑":["链家地产", "我爱我家"] }, "朝阳":{ "望京":["奔驰", "陌陌"], "国贸":["CICC","HP"], "东直门":["Adevetn","飞信"] }, "海淀":{ }, }, "山东":{ "德州":{}, "青岛":{}, "济南":{} }, "广东":{ "东莞":{}, "常熟":{}, "佛山":{} }}exit_flag = Falsewhile not exit_flag: for i in data: print(i) choice = input("选择进入1>>:") if choice in data: while not exit_flag: for i2 in data[choice]: print("\t",i2) choice2 = input("选择进入2>>:") if choice2 in data[choice]: while not exit_flag: for i3 in data[choice][choice2]: print("\t\t",i3) choice3 = input("请选择进入3>>:") if choice3 in data[choice][choice2]: for i4 in data[choice][choice2][choice3]: print("\t\t",i4) choice4 = input("选择进入4>>:") if choice4 == "b": pass elif choice4 == "q": exit_flag = True if choice3 == "b": break elif choice3 == "q": exit_flag = True if choice2 == "b": break elif choice2 == "q": exit_flag = True作业
用户入口
商品信息存在文件里
已购商品，余额记录
商家入口
可以添加商品
可以修改商品价格