数据类型(中)
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- 1.列表(list)
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- [1.1 定义](#1.1 定义)
- [1.2 独有功能](#1.2 独有功能)
- [1.3 公共功能](#1.3 公共功能)
- [1.4 转换](#1.4 转换)
- [1.5. 其他](#1.5. 其他)
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- [1.5.1 嵌套](#1.5.1 嵌套)
- 2.元组
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- [2.1 定义](#2.1 定义)
- [2.2 独有功能](#2.2 独有功能)
- [2.3 公共功能](#2.3 公共功能)
- [2.4 转换](#2.4 转换)
- [2.5 其他](#2.5 其他)
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- [2.5.1 嵌套](#2.5.1 嵌套)
- 总结
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常见的数据类型:
- int,整数类型(整形)
- bool,布尔类型
- str,字符串类型
- list,列表类型
- tuple,元组类型
- dict,字典类型
- set,集合类型
- float,浮点类型(浮点型)
目标:掌握列表和元组数据类型的各种操作(知识点应用案例)。
课程概要:
- list,列表类型,用于存储一些数据的容器(有序 & 可修改)。【80%】
- tuple,元组类型,用于存储一些数据的容器(有序 & 不可修改)。【20%】
1.列表(list)
列表(list),是一个有序 且可变 的容器,在里面可以存放多个不同类型的元素。
1.1 定义
python
user_list = ["苍老师","有坂深雪","大桥未久"]
number_list = [98,88,666,12,-1]
data_list = [1,True,"Alex","宝强","贾乃亮"]
python
user_list = []
user_list.append("铁锤")
user_list.append(123)
user_list.append(True)
print(user_list) # ["铁锤",123,True]
不可变类型:字符串、布尔、整型(已最小,内部数据无法进行修改)
可变类型:列表(内部数据元素可以修改)
1.2 独有功能
Python中为所有的列表类型的数据提供了一批独有的功能。
在开始学习列表的独有功能之前,先来做一个字符串和列表的对比:
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字符串,不可变,即:创建好之后内部就无法修改。【独有功能都是新创建一份数据】
pythonname = "alex" data = name.upper() print(name) print(data)
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列表,可变,即:创建好之后内部元素可以修改。【独有功能基本上都是直接操作列表内部,不会创建新的一份数据】
pythonuser_list = ["车子","妹子"] user_list.append("嫂子") print(user_list) # ["车子","妹子","嫂子"]
列表中的常见独有功能如下:
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追加,在原列表中尾部追加值。
pythondata_list = [] v1 = input("请输入姓名") data_list.append(v1) v2 = input("请输入姓名") data_list.append(v2) print(data_list) # ["alex","eric"]
python# 案例1 user_list = [] while True: user = input("请输入用户名(Q退出):") if user == "Q": break user_list.append(user) print(user_list)
python# 案例2 welcome = "欢迎使用NB游戏".center(30, '*') print(welcome) user_count = 0 while True: count = input("请输入游戏人数:") if count.isdecimal(): user_count = int(count) break else: print("输入格式错误,人数必须是数字。") message = "{}人参加游戏NB游戏。".format(user_count) print(message) user_name_list = [] for i in range(1, user_count + 1): tips = "请输入玩家姓名({}/{}):".format(i, user_count) name = input(tips) user_name_list.append(name) print(user_name_list)
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批量追加,将一个列表中的元素逐一添加另外一个列表。
pythontools = ["搬砖","菜刀","榔头"] tools.extend( [11,22,33] ) # weapon中的值逐一追加到tools中 print(tools) # ["搬砖","菜刀","榔头",11,22,33]
pythontools = ["搬砖","菜刀","榔头"] weapon = ["AK47","M6"] #tools.extend(weapon) # weapon中的值逐一追加到tools中 #print(tools) # ["搬砖","菜刀","榔头","AK47","M6"] weapon.extend(tools) print(tools) # ["搬砖","菜刀","榔头"] print(weapon) # ["AK47","M6","搬砖","菜刀","榔头"]
python# 等价于(扩展) weapon = ["AK47","M6"] for item in weapon: print(item) # 输出: # AK47 # M6 tools = ["搬砖","菜刀","榔头"] weapon = ["AK47","M6"] for item in weapon: tools.append(item) print(tools) # ["搬砖","菜刀","榔头","AK47","M6"]
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插入,在原列表的指定索引位置插入值
pythonuser_list = ["苍老师","有坂深雪","大桥未久"] user_list.insert(0,"马蓉") user_list.insert(2,"李小璐") print(user_list)
python# 案例 name_list = [] while True: name = input("请输入购买火车票用户姓名(Q/q退出):") if name.upper() == "Q": break if name.startswith("刁"): name_list.insert(0, name) else: name_list.append(name) print(name_list)
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在原列表中根据值删除(从左到右找到第一个删除)【慎用,里面没有会报错】
pythonuser_list = ["王宝强","陈羽凡","Alex","贾乃亮","Alex"] user_list.remove("Alex") print(user_list) user_list = ["王宝强","陈羽凡","Alex","贾乃亮","Alex"] if "Alex" in user_list: user_list.remove("Alex") print(user_list) user_list = ["王宝强","陈羽凡","Alex","贾乃亮","Alex"] while True: if "Alex" in user_list: user_list.remove("Alex") else: break print(user_list)
python# 案例:自动抽奖程序 import random data_list = ["iphone12", "二手充气女友", "大保健一次", "泰国5日游", "避孕套"] while data_list: name = input("自动抽奖程序,请输入自己的姓名:") # 随机从data_list抽取一个值出来 value = random.choice(data_list) # "二手充气女友" print( "恭喜{},抽中{}.".format(name, value) ) data_list.remove(value) # "二手充气女友"
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在原列表中根据索引踢出某个元素(根据索引位置删除)
pythonuser_list = ["王宝强","陈羽凡","Alex","贾乃亮","Alex"] # 0 1 2 3 4 user_list.pop(1) print(user_list) # ["王宝强","Alex","贾乃亮","Alex"] user_list.pop() print(user_list) # ["王宝强","Alex","贾乃亮"] item = user_list.pop(1) print(item) # "Alex" print(user_list) # ["王宝强","贾乃亮"]
python# 案例:排队买火车票 # ["alex","李杰","eric","武沛齐","老妖","肝胆"] user_queue = [] while True: name = input("北京~上海火车票,购买请输入姓名排队(Q退出):") if name == "Q": break user_queue.append(name) ticket_count = 3 for i in range(ticket_count): username = user_queue.pop(0) message = "恭喜{},购买火车票成功。".format(username) print(message) # user_queue = ["武沛齐","老妖","肝胆"] faild_user = "、".join(user_queue) # "武沛齐、老妖、肝胆" faild_message = "非常抱歉,票已售完,以下几位用户请选择其他出行方式,名单:{}。".format(faild_user) print(faild_message)
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清空原列表
pythonuser_list = ["王宝强","陈羽凡","Alex","贾乃亮","Alex"] user_list.clear() print(user_list) # []
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根据值获取索引(从左到右找到第一个删除)【慎用,找不到报错】
pythonuser_list = ["王宝强","陈羽凡","Alex","贾乃亮","Alex"] # 0 1 2 3 4 if "Alex" in user_list: index = user_list.index("Alex") print(index) # 2 else: print("不存在")
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列表元素排序
python# 数字排序 num_list = [11, 22, 4, 5, 11, 99, 88] print(num_list) num_list.sort() # 让num_list从小到大排序 num_list.sort(reverse=True) # # 让num_list从大到小排序 print(num_list) # 字符串排序 user_list = ["王宝强", "Ab陈羽凡", "Alex", "贾乃亮", "贾乃", "1"] # [29579, 23453, 24378] # [65, 98, 38472, 32701, 20961] # [65, 108, 101, 120] # [49] print(user_list) """ sort的排序原理 [ "x x x" ," x x x x x " ] """ user_list.sort() print(user_list)
注意:排序时内部元素无法进行比较时,程序会报错(尽量数据类型统一)。
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反转原列表
pythonuser_list = ["王宝强","陈羽凡","Alex","贾乃亮","Alex"] user_list.reverse() print(user_list)
1.3 公共功能
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相加,两个列表相加获取生成一个新的列表。
pythondata = ["赵四","刘能"] + ["宋晓峰","范德彪"] print(data) # ["赵四","刘能","宋晓峰","范德彪"] v1 = ["赵四","刘能"] v2 = ["宋晓峰","范德彪"] v3 = v1 + v2 print(v3) # ["赵四","刘能","宋晓峰","范德彪"]
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相乘,列表*整型 将列表中的元素再创建N份并生成一个新的列表。
pythondata = ["赵四","刘能"] * 2 print(data) # ["赵四","刘能","赵四","刘能"] v1 = ["赵四","刘能"] v2 = v1 * 2 print(v1) # ["赵四","刘能"] print(v2) # ["赵四","刘能","赵四","刘能"]
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运算符in包含
由于列表内部是由多个元素组成,可以通过in来判断元素是否在列表中。
pythonuser_list = ["狗子","二蛋","沙雕","alex"] result = "alex" in user_list # result = "alex" not in user_list print(result) # True if "alex" in user_list: print("在,把他删除") user_list.remove("alex") else: print("不在")
pythonuser_list = ["狗子","二蛋","沙雕","alex"] if "alex" in user_list: print("在,把他删除") user_list.remove("alex") else: print("不在") text = "打倒小日本" data = "日" in text
python# 案例 user_list = ["狗子","二蛋","沙雕","alex"] if "alex" in user_list: print("在,把他删除") user_list.remove("alex") else: print("不在")
python# 案例 user_list = ["王宝强","陈羽凡","Alex","贾乃亮","Alex"] if "Alex" in user_list: index = user_list.index("Alex") user_list.pop(index)
python# 案例:敏感词替换 text = input("请输入文本内容:") # 按时打发第三方科技爱普生豆腐啊;了深刻的房价破阿偶打飞机 forbidden_list = ["草","欧美","日韩"] for item in forbidden_list: text = text.replace(item,"**") print(text)
注意:列表检查元素是否存在时,是采用逐一比较的方式,效率会比较低。
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获取长度
pythonuser_list = ["范德彪","刘华强",'尼古拉斯赵四'] print( len(user_list) )
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索引,一个元素的操作
python# 读 user_list = ["范德彪","刘华强",'尼古拉斯赵四'] print( user_list[0] ) print( user_list[2] ) print( user_list[3] ) # 报错
python# 改 user_list = ["范德彪","刘华强",'尼古拉斯赵四'] user_list[0] = "武沛齐" print(user_list) # ["武沛齐","刘华强",'尼古拉斯赵四']
python# 删 user_list = ["范德彪","刘华强",'尼古拉斯赵四'] del user_list[1] user_list.remove("刘华强") ele = user_list.pop(1)
注意:超出索引范围会报错。
提示:由于字符串是不可变类型,所以他只有索引读的功能,而列表可以进行 读、改、删
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切片,多个元素的操作(很少用)
python# 读 user_list = ["范德彪","刘华强",'尼古拉斯赵四'] print( user_list[0:2] ) # ["范德彪","刘华强"] print( user_list[1:] ) print( user_list[:-1] )
python# 改 user_list = ["范德彪", "刘华强", '尼古拉斯赵四'] user_list[0:2] = [11, 22, 33, 44] print(user_list) # 输出 [11, 22, 33, 44, '尼古拉斯赵四'] user_list = ["范德彪", "刘华强", '尼古拉斯赵四'] user_list[2:] = [11, 22, 33, 44] print(user_list) # 输出 ['范德彪', '刘华强', 11, 22, 33, 44] user_list = ["范德彪", "刘华强", '尼古拉斯赵四'] user_list[3:] = [11, 22, 33, 44] print(user_list) # 输出 ['范德彪', '刘华强', '尼古拉斯赵四', 11, 22, 33, 44] user_list = ["范德彪", "刘华强", '尼古拉斯赵四'] user_list[10000:] = [11, 22, 33, 44] print(user_list) # 输出 ['范德彪', '刘华强', '尼古拉斯赵四', 11, 22, 33, 44] user_list = ["范德彪", "刘华强", '尼古拉斯赵四'] user_list[-10000:1] = [11, 22, 33, 44] print(user_list) # 输出 [11, 22, 33, 44, '刘华强', '尼古拉斯赵四']
python# 删 user_list = ["范德彪", "刘华强", '尼古拉斯赵四'] del user_list[1:] print(user_list) # 输出 ['范德彪']
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步长
pythonuser_list = ["范德彪","刘华强",'尼古拉斯赵四',"宋小宝","刘能"] # 0 1 2 3 4 print( user_list[1:4:2] ) print( user_list[0::2] ) print( user_list[1::2] ) print( user_list[4:1:-1] )
python# 案例:实现列表的翻转 user_list = ["范德彪","刘华强",'尼古拉斯赵四',"宋小宝","刘能"] new_data = user_list[::-1] print(new_data) data_list = ["范德彪","刘华强",'尼古拉斯赵四',"宋小宝","刘能"] data_list.reverse() print(data_list) # 给你一个字符串请实现字符串的翻转? name = "武沛齐" name[::-1]
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for循环
pythonuser_list = ["范德彪","刘华强",'尼古拉斯赵四',"宋小宝","刘能"] for item in user_list: print(item)
pythonuser_list = ["范德彪","刘华强",'尼古拉斯赵四',"宋小宝","刘能"] for index in range( len(user_list) ): item = user_index[index] print(item)
切记,循环的过程中对数据进行删除会踩坑【面试题】。
python# 错误方式, 有坑,结果不是你想要的。 user_list = ["刘的话", "范德彪", "刘华强", '刘尼古拉斯赵四', "宋小宝", "刘能"] for item in user_list: if item.startswith("刘"): user_list.remove(item) print(user_list)
python# 正确方式,倒着删除。 user_list = ["刘的话", "范德彪", "刘华强", '刘尼古拉斯赵四', "宋小宝", "刘能"] for index in range(len(user_list) - 1, -1, -1): item = user_list[index] if item.startswith("刘"): user_list.remove(item) print(user_list)
1.4 转换
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int、bool无法转换成列表
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str
pythonname = "武沛齐" data = list(name) # ["武","沛","齐"] print(data)
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超前
pythonv1 = (11,22,33,44) # 元组 vv1 = list(v1) # 列表 [11,22,33,44] v2 = {"alex","eric","dsb"} # 集合 vv2 = list(v2) # 列表 ["alex","eric","dsb"]
1.5. 其他
1.5.1 嵌套
列表属于容器,内部可以存放各种数据,所以他也支持列表的嵌套,如:
python
data = [ "谢广坤",["海燕","赵本山"],True,[11,22,[999,123],33,44],"宋小宝" ]
对于嵌套的值,可以根据之前学习的索引知识点来进行学习,例如:
python
data = [ "谢广坤",["海燕","赵本山"],True,[11,22,33,44],"宋小宝" ]
print( data[0] ) # "谢广坤"
print( data[1] ) # ["海燕","赵本山"]
print( data[0][2] ) # "坤"
print( data[1][-1] ) # "赵本山"
data.append(666)
print(data) # [ "谢广坤",["海燕","赵本山"],True,[11,22,33,44],"宋小宝",666]
data[1].append("谢大脚")
print(data) # [ "谢广坤",["海燕","赵本山","谢大脚"],True,[11,22,33,44],"宋小宝",666 ]
del data[-2]
print(data) # [ "谢广坤",["海燕","赵本山","谢大脚"],True,[11,22,33,44],666 ]
data[-2][1] = "alex"
print(data) # [ "谢广坤",["海燕","赵本山","谢大脚"],True,[11,"alex",33,44],666 ]
data[1][0:2] = [999,666]
print(data) # [ "谢广坤",[999,666,"谢大脚"],True,[11,"alex",33,44],666 ]
python
# 创建用户列表
# 用户列表应该长: [ ["alex","123"],["eric","666"] ]
# user_list = [["alex","123"],["eric","666"],]
# user_list.append(["alex","123"])
# user_list.append(["eric","666"])
user_list = []
while True:
user = input("请输入用户名:")
pwd = input("请输入密码:")
data = []
data.append(user)
data.append(pwd)
user_list.append(data)
python
user_list = []
while True:
user = input("请输入用户名(Q退出):")
if user == "Q":
break
pwd = input("请输入密码:")
data = [user,pwd]
user_list.append(data)
print(user_list)
2.元组
列表(list),是一个有序 且可变 的容器,在里面可以存放多个不同类型的元素。
元组(tuple),是一个有序 且不可变 的容器,在里面可以存放多个不同类型的元素。
如何体现不可变呢?
记住一句话:《"我儿子永远不能换成是别人,但我儿子可以长大"》
2.1 定义
python
v1 = (11,22,33)
v2 = ("李杰","Alex")
v3 = (True,123,"Alex",[11,22,33,44])
# 建议:议在元组的最后多加一个逗v3 = ("李杰","Alex",)
python
d1 = (1) # 1
d2 = (1,) # (1,)
d3 = (1,2)
d4 = (1,2)
注意:建议在元组的最后多加一个逗号,用于标识他是一个元组。
python
# 面试题
1. 比较值 v1 = (1) 和 v2 = 1 和 v3 = (1,) 有什么区别?
2. 比较值 v1 = ( (1),(2),(3) ) 和 v2 = ( (1,) , (2,) , (3,),) 有什么区别?
(1,2,3)
2.2 独有功能
无
2.3 公共功能
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相加,两个列表相加获取生成一个新的列表。
pythondata = ("赵四","刘能") + ("宋晓峰","范德彪") print(data) # ("赵四","刘能","宋晓峰","范德彪") v1 = ("赵四","刘能") v2 = ("宋晓峰","范德彪") v3 = v1 + v2 print(v3) # ("赵四","刘能","宋晓峰","范德彪")
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相乘,列表*整型 将列表中的元素再创建N份并生成一个新的列表。
pythondata = ("赵四","刘能") * 2 print(data) # ("赵四","刘能","赵四","刘能") v1 = ("赵四","刘能") v2 = v1 * 2 print(v1) # ("赵四","刘能") print(v2) # ("赵四","刘能","赵四","刘能")
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获取长度
pythonuser_list = ("范德彪","刘华强",'尼古拉斯赵四',) print( len(user_list) )
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索引
pythonuser_list = ("范德彪","刘华强",'尼古拉斯赵四',) print( user_list[0] ) print( user_list[2] ) print( user_list[3] )
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切片
pythonuser_list = ("范德彪","刘华强",'尼古拉斯赵四',) print( user_list[0:2] ) print( user_list[1:] ) print( user_list[:-1] )
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步长
pythonuser_list = ("范德彪","刘华强",'尼古拉斯赵四',"宋小宝","刘能") print( user_list[1:4:2] ) print( user_list[0::2] ) print( user_list[1::2] ) print( user_list[4:1:-1] )
python# 字符串 & 元组。 user_list = ("范德彪","刘华强",'尼古拉斯赵四',"宋小宝","刘能") data = user_list[::-1] # 列表 user_list = ["范德彪","刘华强",'尼古拉斯赵四',"宋小宝","刘能"] data = user_list[::-1] user_list.reverse() print(user_list)
-
for循环
pythonuser_list = ("范德彪","刘华强",'尼古拉斯赵四',"宋小宝","刘能") for item in user_list: print(item)
pythonuser_list = ("范德彪","刘华强",'尼古拉斯赵四',"宋小宝","刘能") for item in user_list: if item == '刘华强': continue print(name)
目前:只有 str、list、tuple 可以被for循环。 "xxx" [11,22,33] (111,22,33)
python# len + range + for + 索引 user_list = ("范德彪","刘华强",'尼古拉斯赵四',"宋小宝","刘能") for index in range(len(user_list)): item = user_list[index] print(item)
2.4 转换
其他类型转换为元组,使用tuple(其他类型)
,目前只有字符串和列表可以转换为元组。
python
data = tuple(其他)
# str / list
python
name = "武沛齐"
data = tuple(name)
print(data) # 输出 ("武","沛","齐")
python
name = ["武沛齐",18,"pythonav"]
data = tuple(name)
print(data) # 输出 ("武沛齐",18,"pythonav")
2.5 其他
2.5.1 嵌套
由于元组和列表都可以充当容器
,他们内部可以放很多元素,并且也支持元素内的各种嵌套。
python
tu = ( '今天姐姐不在家', '姐夫和小姨子在客厅聊天', ('姐夫问小姨子税后多少钱','小姨子低声说道说和姐夫还提钱') )
tu1 = tu[0]
tu2 = tu[1]
tu3 = tu[2][0]
tu4 = tu[2][1]
tu5 = tu[2][1][3]
print(tu1) # 今天姐姐不在家
print(tu2) # 姐夫和小姨子在客厅聊天
print(tu3) # 姐夫问小姨子税后多少钱
print(tu4) # 小姨子低声说道说和姐夫还提钱
练习题1:判断是否可以实现,如果可以请写代码实现。
python
li = ["alex", [11,22,(88,99,100,),33], "WuSir", ("ritian", "barry",), "wenzhou"]
# 0 1 2 3 4
# 1.请将 "WuSir" 修改成 "武沛齐"
li[2] = "武沛齐"
index = li.index("Wusir")
li[index] = "武沛齐"
# 2.请将 ("ritian", "barry",) 修改为 ['日天','日地']
li[3] = ['日天','日地']
# 3.请将 88 修改为 87
li[1][2][0] = 87 # (报错,)
# 4.请将 "wenzhou" 删除,然后再在列表第0个索引位置插入 "周周"
# li.remove("wenzhou")
# del li[-1]
li.insert(0,"周周")
练习题2:记住一句话:《"我儿子永远不能换成是别人,但我儿子可以长大"》
python
data = ("123",666,[11,22,33], ("alex","李杰",[999,666,(5,6,7)]) )
# 1.将 "123" 替换成 9 报错
# 2.将 [11,22,33] 换成 "武沛齐" 报错
# 3.将 11 换成 99
data[2][0] = 99
print(data) # ("123",666,[99,22,33], ("alex","李杰",[999,666,(5,6,7)]) )
# 4.在列表 [11,22,33] 追加一个44
data[2].append(44)
print(data) # ("123",666,[11,22,33,44], ("alex","李杰",[999,666,(5,6,7)]) )
练习题3:动态的创建用户并添加到用户列表中。
python
# 创建用户 5个
# user_list = [] # 用户信息
user_list = [ ("alex","132"),("admin","123"),("eric","123") ]
while True:
user = input("请输入用户名:")
if user == "Q":
brek
pwd = input("请输入密码:")
item = (user,pwd,)
user_list.append(item)
# 实现:用户登录案例
print("登录程序")
username = input("请输入用户名:")
password = input("请输入密码:")
is_success = False
for item in user_list:
# item = ("alex","132") ("admin","123") ("eric","123")
if username == item[0] and password == item[1]:
is_success = True
break
if is_success:
print("登录成功")
else:
print("登录失败")
总结
- 概述
- 列表,以后写程序会用的非常多,要多些多练。
- 元组,以后写程序用的不是很多,主要以了解其特殊和用法为主。
- 列表和元组的区别。
- 可变类型和不可变类型。
- 列表独有功能 & 公共功能(不用特地去记,多做题目去用,以后每天都会有相关的练习题)。
- 列表和元组等数据的嵌套
- 元组中 (1) 和 (1,) 的区别。
- 元组的元素不能被替换,但元组的元素如果是可变类型,可变类型内部是可以修改的。