python基础，python第二课
python基础第二天的课程，主要内容列表，元祖，字典，字符串等主要内容
列表
定义列表
>>> names = ["ZhangSan","LiSi","WangWu","ZhaoLiu",["ZhangXin","MengDong"],"ZongQi","HeiBa","DongJiu"] >>> print(names) ['ZhangSan', 'LiSi', 'WangWu', 'ZhaoLiu', ['ZhangXin', 'MengDong'], 'ZongQi', 'HeiBa', 'DongJiu']
列表取值
>>> names[0] #names列表元素从左往右，从0开始数 'ZhangSan' >>> names[4][0] 'ZhangXin'
列表切片
>>> print(names[0]) ZhangSan >>> print(names[0:]) #从第一个元素取到最末 ['ZhangSan', 'LiSi', 'WangWu', 'ZhaoLiu', ['ZhangXin', 'MengDong'], 'ZongQi', 'HeiBa', 'DongJiu'] >>> print(names[-1]) #取最后一个元素 DongJiu >>> print(names[:-1]) #从第一个元素取到最后一个（不包含最后一个） ['ZhangSan', 'LiSi', 'WangWu', 'ZhaoLiu', ['ZhangXin', 'MengDong'], 'ZongQi', 'HeiBa'] >>> print(names[-2:]) #取最后两个元素 ['HeiBa', 'DongJiu'] >>> print(names[:4]) #取前4个元素 ['ZhangSan', 'LiSi', 'WangWu', 'ZhaoLiu'] >>> print(names[-4:]) #取后四个元素 [['ZhangXin', 'MengDong'], 'ZongQi', 'HeiBa', 'DongJiu'] >>> print(names[::2]) #从头开始取，2代表，每隔一个取一个。 如果是3，每两个取一个，以此类推 ['ZhangSan', 'WangWu', ['ZhangXin', 'MengDong'], 'HeiBa']
列表的操作
>>> names.append("DaWa") #在列表内最后追加 >>> print(names) ['ZhangSan', 'LiSi', 'WangWu', 'ZhaoLiu', ['ZhangXin', 'MengDong'], 'ZongQi', 'HeiBa', 'DongJiu', 'DaWa']
names.insert(1,"ErWa") #在下标位置为1的元素前插入 >>> print(names) ['ZhangSan', 'ErWa', 'LiSi', 'WangWu', 'ZhaoLiu', ['ZhangXin', 'MengDong'], 'ZongQi', 'HeiBa', 'DongJiu', 'DaWa']
>>> names[1]="SanWa" >>> print(names) ['ZhangSan', 'SanWa', 'LiSi', 'WangWu', 'ZhaoLiu', ['ZhangXin', 'MengDong'], 'ZongQi', 'HeiBa', 'DongJiu', 'DaWa']
>>> del names[0] #删除元素下标位置的数据 >>> print(names) ['SanWa', 'LiSi', 'WangWu', 'ZhaoLiu', ['ZhangXin', 'MengDong'], 'ZongQi', 'HeiBa', 'DongJiu', 'DaWa'] >>> names.remove("DaWa") #删除指定数据 >>> print(names) ['SanWa', 'LiSi', 'WangWu', 'ZhaoLiu', ['ZhangXin', 'MengDong'], 'ZongQi', 'HeiBa', 'DongJiu'] >>> names.pop() #删除最后一个数据 'DongJiu' >>> print(names) ['SanWa', 'LiSi', 'WangWu', 'ZhaoLiu', ['ZhangXin', 'MengDong'], 'ZongQi', 'HeiBa']
>>> print(names) ['SanWa', 'LiSi', 'WangWu', 'ZhaoLiu', ['ZhangXin', 'MengDong'], 'ZongQi', 'HeiBa'] >>> names2=["1","2","3","4","5","6","LiSi"] >>> names.extend(names2) #在names列表数据后面追加names2的数据 >>> print(names) ['SanWa', 'LiSi', 'WangWu', 'ZhaoLiu', ['ZhangXin', 'MengDong'], 'ZongQi', 'HeiBa', '1', '2', '3', '4', '5', '6', 'LiSi']
>>> names1 = ['one','two','three','four',["five","six"],7,8,9,] >>> names2 = names1.copy() >>> print(names2) ['one', 'two', 'three', 'four', ['five', 'six'], 7, 8, 9] >>> names2[4][1]= "none" #修改name2列表中的列表数据后，names1中的值也跟着修改 >>> print(names1) ['one', 'two', 'three', 'four', ['five', 'none'], 7, 8, 9] >>> print(names2) ['one', 'two', 'three', 'four', ['five', 'none'], 7, 8, 9]
>>> names=["LiSi","1","2","3","4","5","6","LiSi"] >>> names.count("LiSi") 2
>>> names = ['one','two','three','four',"7","8","9"] >>> names.sort() >>> print(names) #按ASCII编码排序 ['7', '8', '9', 'four', 'one', 'three', 'two']
>>> names = ['one','two','three','four',"7","8","9"] >>> names.reverse() >>> print(names) ['9', '8', '7', 'four', 'three', 'two', 'one']
>>> names ['9', '8', '7', 'four', 'three', 'two', 'one'] >>> names.index("four") #获取该元素下标值 3
元组
元组tuple和列表十分类似，只不过元组和字符串一样是不可变的，即你不能修改元组。
定义元组
>>> t_name = ("zhang","li","wang","zhao","sun") >>> print(t_name) ('zhang', 'li', 'wang', 'zhao', 'sun')
元组操作
统计
>>> t_name = ("zhang","li","wang","zhao","sun") >>> t_name.count("sun") 1
获取下标
>>> t_name.index("wang") 2
购物车练习
- 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，打印已购买商品和余额
1 shoping_list = [ 2 ('iphone',5800), 3 ('Mac Pro', 16000), 4 ("bike", 800), 5 ("python book", 58), 6 ] 7 curt_list = [] #购物车列表 8 salary = input("你的工资是多少：") 9 if salary.isdigit(): #判断是否是整数 10 salary = int(salary) #转整型 11 while True: 12 for index,item in enumerate(shoping_list): #循环打印商品列表 13 # print(shoping_list.index(item),item) 14 print(index,item) 15 choice_number = input("请输入你要选择的编号:") 16 if choice_number.isdigit(): 17 choice_number = int(choice_number) 18 if choice_number < len(shoping_list) and choice_number >=0: #判断选择编号是否存在 19 p_item = shoping_list[choice_number] #选择商品 20 if p_item[1] <= salary: #判断 商品价格小于等于工资 购买，否则提示余额不足 21 curt_list.append(p_item) #加入购物车 22 salary -=p_item[1] #剩余余额 23 print("\033[31;1m%s\033[0m已经加入购物车,你的余额是\033[32;1m%s\033[0m"%(p_item[0],salary)) 24 else: 25 print("你的余额不足") 26 else: 27 print("你输入的商品不存在") 28 elif choice_number == "q": 29 print("——————shop list——————") 30 for i in curt_list: 31 print(i) 32 print("您的余额是%s"%salary) 33 exit() 34 else: 35 print("你的输入有误") 36 37 else: 38 print("你的输入有误")
字符串
name = "Zhangxin Hanchuan" print(name.capitalize()) print(name.casefold()) print(name.center(20,"-")) print(name.count("s")) print(name.encode()) print(name.endswith("aa")) print(name.find("1")) print(name.format_map({"name":"zhangxin","age":18})) print(name.format(name= "zhangxin",age= 19)) print(name.isalnum()) #是否阿拉伯数字+阿拉伯字符 print("abc".isalpha()) #是否纯英文字符 print("10101010".isdecimal()) #是否十进制 print("abc".isdigit()) #是否整数 print("abc".isidentifier()) #是否是合法变量名，合法标识符 print("Abc Is".islower()) #是否是小写 print("Abc Is".istitle()) #是否是大写 print("123411121".isnumeric()) #是否是数字，和isdigit没区别 print("asdfasdf".isprintable()) #是否可以打印 is tty file，drive file print(" ".isspace()) # 是否是个空格 print("+".join(["1","2","3","4"])) # 是否是列表中加入"+" 字符 print(name.ljust(30,"-")) # 右侧补全20个字符-- print(name.lower()) print("\n ab\n ".strip()) #去掉空格和换行 print(name.replace("a","A")) print(name.rfind("a")) print(name.split("a")) print("a+b+c+d".split("+")) print("zhang xin".swapcase())
字典
字典（dictionary），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。
字典定义
info = { "stdu1101" : "Wuteng Lan", "stdu1102" : "Maliya XiaoZe", "stdu1103" : "Duoyejiyi Bo", "stdu1104" : "LongZe Luola", }
字典特性
- 字典是没有顺序的
- key的值是唯一，天生去重复
增加
>>> info["stdu1105"]= "苍井空"
>>> info
{'stdu1101': 'Wuteng Lan', 'stdu1102': 'Maliya XiaoZe', 'stdu1103': 'Duoyejiyi Bo', 'stdu1104': 'LongZe Luola', 'stdu1105': '苍井空'}
修改
>>> info["stdu1101"]= "波多野结衣" >>> info {'stdu1101': '波多野结衣', 'stdu1102': 'Maliya XiaoZe', 'stdu1103': 'Duoyejiyi Bo', 'stdu1104': 'LongZe Luola', 'stdu1105': '苍井空'}
删除
>>> info.pop("stdu1101") '波多野结衣' >>> del info["stdu1102"] >>> info {'stdu1103': 'Duoyejiyi Bo', 'stdu1104': 'LongZe Luola', 'stdu1105': '苍井空'} >>> info.popitem() #随机删除一个元素 ('stdu1105', '苍井空')
查找
>>> info {'stdu1103': 'Duoyejiyi Bo', 'stdu1104': 'LongZe Luola'} >>> "stdu1103" in info #标准查找 True >>> info.get("stdu1103") #获取 'Duoyejiyi Bo' >>> info["stdu1103"] #同样获取 'Duoyejiyi Bo'>>> print(info.get("stdu1105"))#获取不存在的元素返回None None >>> info["stdu1105"]#获取不存在的元素返回错误 Traceback (most recent call last): File "<pyshell#165>", line 1, in <module> info["stdu1105"] KeyError: 'stdu1105'
多层嵌套字典
>>> litle_dict = { "欧美": { "德国": ["工业4.0", "严谨"], "美国": ["很牛逼", "很自大"], "法国": ["很浪漫", "很懒"], "英国": ["足球流氓很多", "它要脱欧"] }, "日韩": { "日本": ["AV不错", "汽车不错"] }, "大陆": { "中国大陆": ["足球垃圾", "高铁牛逼"] } } >>> litle_dict {'欧美': {'德国': ['工业4.0', '严谨'], '美国': ['很牛逼', '很自大'], '法国': ['很浪漫', '很懒'], '英国': ['足球流氓很多', '它要脱欧']}, '日韩': {'日本': ['AV不错', '汽车不错']}, '大陆': {'中国大陆': ['足球垃圾', '高铁牛逼']}}
修改
>>> litle_dict["欧美"]["美国"][1] = "特朗普" >>> litle_dict {'欧美': {'德国': ['工业4.0', '严谨'], '美国': ['很牛逼', '特朗普'], '法国': ['很浪漫', '很懒'], '英国': ['足球流氓很多', '它要脱欧']}, '日韩': {'日本': ['AV不错', '汽车不错']}, '大陆': {'中国大陆': ['足球垃圾', '高铁牛逼']}}
字典的其他操作
>>> info = { "stdu1101" : "Wuteng Lan", "stdu1102" : "Maliya XiaoZe", "stdu1103" : "Duoyejiyi Bo", "stdu1104" : "LongZe Luola", } >>> info.keys <built-in method keys of dict object at 0x0000000002F47DC8> >>> info.keys() #列表的key值 dict_keys(['stdu1101', 'stdu1102', 'stdu1103', 'stdu1104']) >>> info.values() dict_values(['Wuteng Lan', 'Maliya XiaoZe', 'Duoyejiyi Bo', 'LongZe Luola']) >>> info.items() dict_items([('stdu1101', 'Wuteng Lan'), ('stdu1102', 'Maliya XiaoZe'), ('stdu1103', 'Duoyejiyi Bo'), ('stdu1104', 'LongZe Luola')]) >>> info.setdefault("stdu1105","苍井空") #不存在的参数设置默认值 '苍井空' >>> info {'stdu1101': 'Wuteng Lan', 'stdu1102': 'Maliya XiaoZe', 'stdu1103': 'Duoyejiyi Bo', 'stdu1104': 'LongZe Luola', 'stdu1105': '苍井空'} >>> info.setdefault("stdu1101","武藤兰")#存在的参数设置默认值不生效 'Wuteng Lan' >>> info {'stdu1101': 'Wuteng Lan', 'stdu1102': 'Maliya XiaoZe', 'stdu1103': 'Duoyejiyi Bo', 'stdu1104': 'LongZe Luola', 'stdu1105': '苍井空'} >>> b = {1:2,3:4,"stdu1102":"小泽玛丽亚"} >>> info.update(b)#合并数据，并替换存在参数的数据 >>> info {'stdu1101': 'Wuteng Lan', 'stdu1102': '小泽玛丽亚', 'stdu1103': 'Duoyejiyi Bo', 'stdu1104': 'LongZe Luola', 'stdu1105': '苍井空', 1: 2, 3: 4} >>> dict.fromkeys([1,2,3],"test") #坑多慎用 {1: 'test', 2: 'test', 3: 'test'}
循环dict
>>> info {'stdu1101': 'Wuteng Lan', 'stdu1102': '小泽玛丽亚', 'stdu1103': 'Duoyejiyi Bo', 'stdu1104': 'LongZe Luola', 'stdu1105': '苍井空', 1: 2, 3: 4} >>> for key in info: print(key,info[key]) stdu1101 Wuteng Lan stdu1102 小泽玛丽亚 stdu1103 Duoyejiyi Bo stdu1104 LongZe Luola stdu1105 苍井空 1 2 3 4 >>> for k,v in info.items(): #info内容比较大的时候 不建议使用，info.item()转换需要花费很多时间 print(k,v) stdu1101 Wuteng Lan stdu1102 小泽玛丽亚 stdu1103 Duoyejiyi Bo stdu1104 LongZe Luola stdu1105 苍井空 1 2 3 4
三级菜单练习
- 打印省、市、县三级菜单
- 可返回上一级
- 可随时退出程序
1 menu = { 2 "北京":{ 3 "通州":{ 4 "梨园":{ 5 "蓝岛": {}, 6 "贵友大厦": {}, 7 }, 8 "永顺":{ 9 "京杭府": {}, 10 "北京one": {}, 11 }, 12 "台湖":{ 13 "印象台湖": {}, 14 "台湖政府": {}, 15 }, 16 }, 17 "房山": { 18 "长阳": {}, 19 "良乡": {}, 20 "青龙湖": {}, 21 }, 22 "海淀": { 23 "牡丹园": {}, 24 "中关村": {}, 25 "学院路": {}, 26 }, 27 28 }, 29 "天津": { 30 }, 31 "上海": { 32 }, 33 } 34 35 exit_flag = False 36 37 while not exit_flag: 38 for a in menu: 39 print(a) 40 district = input("请输入城市名称：") 41 if district in menu: 42 while not exit_flag: 43 for b in menu[district]: 44 print("\t",b) 45 town = input("请输入区、县名称：") 46 if town in menu[district]: 47 while not exit_flag: 48 for c in menu[district][town]: 49 print("\t\t",c) 50 hot_business_area = input("请输入城镇名称：") 51 if hot_business_area in menu[district][town]: 52 for d in menu[district][town][hot_business_area]: 53 print("\t\t\t",d) 54 end = input("最后一层了，按b返回") 55 if end == "b": 56 pass 57 elif end =="q": 58 exit_flag = True 59 if hot_business_area == "b": 60 break 61 elif hot_business_area == "q": 62 exit_flag = True 63 if town == "b": 64 break 65 elif town == "q": 66 exit_flag = True
作业
一、元素分类
有如下值集合 [11,22,33,44,55,66,77,88,99,90...]，将所有大于 66 的值保存至字典的第一个key中，将小于 66 的值保存至第二个key的值中。
即： {'k1': 大于66的所有值, 'k2': 小于66的所有值}
L = [11,22,33,44,55,66,77,88,99,90] v1 = [] v2 = [] S = {"k1":v1,"k2":v2} for s1 in L: # print(s1) if s1 <= 66: v1.append(s1) else: s1 > 66: v2.append(s1) print(S)
二、查找
查找列表中元素，移除每个元素的空格，并查找以 a或A开头 并且以 c 结尾的所有元素。
1 li = ["alec", " aric", "Alex", "Tony", "rain"] 2 tu = ("alec", " aric", "Alex", "Tony", "rain") 3 dic = {'k1': "alex", 'k2': ' aric', "k3": "Alex", "k4": "Tony"} 4 for i in li: 5 j = i.strip() 6 if (j.startswith("a") or and j.startswith("A")) j.endswith("c"): 7 print(j) 8 9 for i in tu: 10 j = i.strip() 11 if (j.startswith("a") or and j.startswith("A")) j.endswith("c"): 12 print(j) 13 14 for keys in dic: 15 j = dic[keys].strip() 16 # print(keys,j) 17 if j.startswith("a") and j.endswith("c"): 18 print(j)
三、输出商品列表，用户输入序号，显示用户选中的商品
商品 li = ["手机", "电脑", '鼠标垫', '游艇']
1 goods_list = ["手机","电脑","鼠标垫","游艇"] 2 3 for k, v in enumerate(goods_list, 1): 4 print(k, v) 5 6 while True: 7 number = input("请输入序号:") 8 if number.isdigit(): 9 number = int(number) 10 if number > 0 and number <= len(goods_list): 11 print(goods_list[number-1]) 12 else: 13 print("你输入的序号不存在！") 14 continue 15 else: 16 print("你输入的不是数字") 17 continue
四、购物车
功能要求：
要求用户输入总资产，例如：2000
显示商品列表，让用户根据序号选择商品，加入购物车
购买，如果商品总额大于总资产，提示账户余额不足，否则，购买成功。
附加：可充值、某商品移除购物车
goods = [
{"name": "电脑", "price": 1999},
{"name": "鼠标", "price": 10},
{"name": "游艇", "price": 20},
{"name": "美女", "price": 998},
]
1 total = 20000 2 shopping_cart ={} 3 sum_shopping_price = 0 4 goods = [ 5 {"name": "电脑", "price": 1999}, 6 {"name": "鼠标", "price": 10}, 7 {"name": "游艇", "price": 20}, 8 {"name": "美女", "price": 998}, 9 ] 10 for i in goods: 11 print(i["name"], i["price"]) 12 13 while True: 14 choice_goods = input("请选择商品：\n(结算（j）：") 15 # 循环所有商品，查找需要的商品 16 if choice_goods == "j": 17 break 18 for item in goods: 19 if item["name"] == choice_goods: 20 # 选择商品加入购物车 21 name = item["name"] 22 if name not in shopping_cart.keys(): 23 shopping_cart[name] = { 24 "single_price": item['price'], 25 "num": 1, 26 } 27 print("%s加入购物车" % name) 28 else: 29 shopping_cart[name]["num"] += 1 30 print("%s该商品购买%s件" % (name, shopping_cart[name]["num"])) 31 # print(shopping_cart) 32 for k, v in shopping_cart.items(): 33 #{ 34 # '电脑': {'single_price': 1999, 'num': 1}, 35 # '鼠标': {'single_price': 10, 'num': 1}, 36 # '美女': {'single_price': 998, 'num': 1} 37 # } 38 x = v['single_price'] 39 y = v['num'] 40 single_shopping_price = x * y 41 sum_shopping_price += 1 42 43 if sum_shopping_price < total: 44 45 print("以下商品%s购买成功，剩余%s" % (shopping_cart,total-sum_shopping_price)) 46 else: 47 print("余额不足")
五、用户交互，显示省市县三级联动的选择
dic = {
"河北": {
"石家庄": ["鹿泉", "藁城", "元氏"],
"邯郸": ["永年", "涉县", "磁县"],
},
"河南": {
"郑州": ["鹿泉1", "藁城1", "元氏1"],
"洛阳": ["永年1", "涉县1", "磁县1"],
},
"山西": {
"太远": ["鹿泉2", "藁城2", "元氏2"],
"大同": ["永年2", "涉县2", "磁县2"],
}
}
1 dic = { 2 "河北": { 3 "石家庄": ["鹿泉", "藁城", "元氏"], 4 "邯郸": ["永年", "涉县", "磁县"], 5 }, 6 "河南": { 7 "郑州": ["鹿泉1", "藁城1", "元氏1"], 8 "洛阳": ["永年1", "涉县1", "磁县1"], 9 }, 10 "山西": { 11 "太远": ["鹿泉2", "藁城2", "元氏2"], 12 "大同": ["永年2", "涉县2", "磁县2"], 13 } 14 } 15 while True: 16 for k in dic: 17 print(k) 18 i1 = input("请选择省份：") 19 if i1 in dic.keys(): 20 #地级市 21 one_city = dic[i1] 22 for v in one_city: 23 print(v) 24 i2 = input("请选择地级市：") 25 if i2 in one_city: 26 #县城 27 two_city = dic[i1][i2] 28 for z in two_city: 29 print(z) 30 break 31 else: 32 print("你输入省份不存在") 33 continue
