Learn Python quickly in 7 days - Day 3

[Learn Python quickly in 7 days - Day 3]

3 data types

布尔值（bool）：True  False

整型（int）	  ：1 19 22 300

字符串（str） ："中国联通" 
	upper/lower/isdecimal/strip/lstrip/rstrip/replace/
	join/split/center/ljust/rjust/zfill
	len/索引/切片/for循环

列表（list）  ：[11,22,33]   ["李冉","谢鹏","陈青",11, 22 ,True]
	append/insert/remove/pop/clear/sort
	len/索引/切片/for循环

元组（tuple） ：(11,22,33)   ("李冉","谢鹏","陈青",11, 22 ,True)

字典（dict）  ：{ "k1":123 , "k2":456 }  {"n1":1,"N2":True}

n1 = "root"
res = n1.upper()    # res = "ROOT"

n2 = "admin"
value = n2.upper()  # value = "ADMIN"

data_list1 = [11,22,33,44]
data_list1.append(55)  # 列表的功能，在列表的尾部追加某个值 [11,22,33,44,55]

data_list2 = [1,2,3]
data_list2.append(55)  # 列表的功能，在列表的尾部追加某个值 [1,2,3,55]

Today’s summary:

• string type
• list type
• tuple type

1. String (str)

1.1 Definition

v = "xxxx"

1.2 Unique features

1. uppercase a.upper()

2. Lowercase a.lower()

3. Whether it is a number a.isdecimal

4. Replace a.replace("1","2")

5. Remove whitespace/left/right a.stript().lstript().rstript()

6. cutting

   file_name = "day01 python基础编程入门.mp4"
   
   # 切割字符串后得到的是一个列表
   #                       0                   1  
   # data_list = [ "day01 python基础编程入门" , "mp4"  ]
   data_list = file_name.split(".")//flie.split(".")
   
   data_list[0]    # "day01 python基础编程入门"
   data_list[1]    # "mp4"
   

   text = "武沛齐,root,[email protected],19"
   
   #    0       1           2            3
   # ["武沛齐","root","[email protected]","19"]
   
   data_list = text.split(",")
   data_list[0]
   data_list[1]
   data_list[2]
   data_list[3]
   

7. Splicing

   # 1.字符串相加
   v1 = "鲁番吐"
   v2 = "大神"
   
   text = v1 + "是" + v2
   

   # 2.字符串格式化
   v1 = "鲁番吐"
   v2 = "大神"
   text = "{}是{}".format(v1,v2)
   

   # 3.列表，里面有很多字符串，你想要让他们按照某个连接符拼接起来。注意事项：想要通过join去拼接，列表中必须都是字符串。
   
   data_list = ["一","二","三","四"]
   
   res = "_".join(data_list)
   print(res) # "一_二_三_四"
   a = "_".join(list)
   

   data_list = ["一","二","三","四"]
   
   res = ",".join(data_list)
   print(res) #  "一，二，三，四"
   

   data_list = ["一","二","三","四"]
   
   res = "".join(data_list)
   print(res) # "一二三四"
   

   Note: If you want to join through join, the list must all be strings.

8. Convert string to byte type

   字符串		 unicode
   字节		 utf-8/gbk（文件存储、网络传输）
   

   data = "中国联通"
   v1 = data.encode("utf-8")//"中国联通"压缩的值
   print(v1) 
   # b'  \xe4       \xb8      \xad \xe5\x9b\xbd \xe8\x81\x94 \xe9\x80\x9a'
   #   01110010   10111000
   

   text = v1.decode("utf-8")//"中国联通"解压的值
   print(text) # "中国联通"
   

9. length complement

   name = "宁摆场"
   
   text = name.center(13,"*")//居中，总长度为13
   print(text) # "*****宁摆场*****"
   

   name = "宁摆场"
   
   text = name.ljust(13,"#")//原值放左边
   print(text) # "宁摆场##########"
   

   name = "宁摆场"
   
   text = name.rjust(13,"#")//原值放右边
   print(text) # "##########宁摆场"
   

10. The complement of length can only be padded with 0 on the left (0 is padded in front of a binary string)

    name = "吐鲁番"
    
    v1 = name.zfill(10)//补足，总长度为10，，，，zfill
    print(v1) # "0000000卢红萍"
    

    data = "10101"
    
    res = data.zfill(8)
    print(res) # "00010101"
    

Practice questions

1. Write code to implement it, prompting the user to enter text, you can judge whether the text starts with "China", enter: Chinese, otherwise foreigner.

   text = input(">>>")
   if text.startswith("中国")://a.startswith("中国')
       print("中国人")
   else:
       print("外国人")
   

2. Write code to implement it, prompt the user to enter text, and replace upper with lower in the text.

   text = input(">>>")
   res = text.replace("上","下")//替换a.replace("上","下")
   print(res)
   

3. Prompts the user to enter two numbers to add, for example: 5+2, 6+9 format (do not consider yy+77).

   #            0  1
   data_list = [11, 9]
   data_list[0]
   data_list[1]
   

   text = input(">>>")   # "5+9"//5+9
   data_list = text.split("+")  # ["5","9"]//data = a.split("+")
   
   res = int(data_list[0]) + int(data_list[1])//int(data[0]) + int(data[1])
   print(res)
   

4. Prompts the user to input two numbers to add, for example: 5+2, 6+9, Hello+9. If it is judged that they are all numbers, the numbers will be added. As long as any one is not a number, an input error will be prompted.

   text = input(">>>")   # "5+9"
   data_list = text.split("+")  # ["5","9"]
   
   if data_list[0].isdecimal() and data_list[1].isdecimal()://isdecimal()
       res = int(data_list[0]) + int(data_list[1])
       print(res)
   else:
       print("输入错误")
   

5. Queue to buy tickets

   # ["罗小春","谢鹏",龚星云]
   name_list = []
   name_list.append("罗小春")  
   name_list.append("谢鹏")  
   name_list.append("龚星云")  
   
   # name_list = ["罗小春","谢鹏",龚星云]
   

   # 1.循环让用户输入姓名（q/Q终止），每输入一个姓名都追加到列表中。
   
   # 2.输入q退出之后，将所有的人员姓名通过逗号连接成字符串并输出。
   

   user_list = []
   while True://while True:a = input()
       name = input("请输入姓名：")//if a.upper() == "Q"
       if name.upper() == "Q":
           break
       user_list.append(name)
       
   res = ",".join(user_list)//b = ",".join(user_list)
   print(res)
   

1.3 Public functions

1. Length a = len("str")

   name = "欧阳娜娜"
   
   res = len(name)
   print(res) # 4
   

   v1 = len("陆梅yy8899")
   print(v2) # 8
   

2. index

   #       0  1 2  3 4  5 6 7 8 9 10 11
   text = "我 要 学 习 P y t h o n 编 程"
   
   text[0] # "我"
   text[8] # "o"
   text[10] # "编"
   
   v1 = 3
   text[v1] # "习"
   
   text[100] # 报错，不能超出范围取值
   
   v2 = len(text) - 1 # 12
   text[v2]  # "程"
   

   text = "我要学习python编程"
   index = 0
   while index < len(text):
       print(text[index])
       index += 1
   

   #       0  1 2  3 4  5 6 7 8 9 10 11
   #                           -3 -2 -1
   text = "我 要 学 习 P y t h o n 编 程"
   
   text[-1]  # "程"
   

3. Slicing // Take before and after without taking, the string cannot be changed, slicing is a copy of the original string cut out

   #       0  1  2  3 4  5 6 7 8 9 10 11
   #                           -3 -2 -1
   text = "我 要 学 习 P y t h o n 编 程"
   
   text[0:2]  # "我要"
   text[2:8]  # "学习Pytho"
   text[2:-1]  # "学习Python编"
   text[2:]  # "学习Python编程"//从2开始到最后
   text[:-1]  # "我要学习Python编"//从开始到编
   text[:]  # "我要学习Python编程"//全部
   
   # 注意：1.前取后不取；   2.索引位置是从0开始。
   

   num = 189
   
   # 1.转换成二进制的字符串
   bin_string = bin(num)   # '0b10111101'
   
   # 2.不要0b， data="10111101"
   data = bin_string[2:]
   
   # 3.将二进制字符串补足16位，在他的前面补0
   result = data.zfill(16)
   print(result) # "0000000010111101"
   

4. cycle

   给你一个字符串 data = "我要学习Python编程" ，让你循环字符串中的每个元素。
   - while循环+索引
   - for循环
   

   • while loop

     data = "我要学习Python编程"
     
     index = 0
     while index < len(data):
         char = data[index]
         print(char)
         index += 1
     

   • for loop, get it directly.

     data = "我要学习Python编程"//字符串
     
     for item in data://for i in data:  print(i)
         print(item)
     

     data = [11,22,33,44,55,66]//列表
     
     for item in data:
         print(item)
         ..
         ..
         ...
     

     # range函数作用，帮助你生成一个数字列表。从0开始，前取后不取
     v1 = range(5)        # [0,1,2,3,4]//0-4
     v2 = range(5,10)     # [5,6,7,8,9]//5-9
     v3 = range(5,10,2)   # [5,7,9]//5，7，9
     v5 = range(10,0,-1)  # [10,9,8,7,6,5,4,3,2,1]//10-1
     

     for item in range(5): # [0,1,2,3,4]
         print(item)
         
     for item in range(5,10): # [5,6,7,8,9]
         print(item)
         
     for item in range(10,0,-1): # [10,9,8,7,6,5,4,3,2,1]
         print(item) 
     

     # 请实现获取字符串中的每个元素并输出。
     data = "我要学习Python编程"
     
     # 方式1
     index = 0
     while index < len(data):
         char = data[index]
         print(char)
         index += 1
         
     # 方式2
     for item in data:
         print(item)
         
     # 方式3
     for idx in range(len(data)): # [0,1,2,3,4,5,6,7,8,9,10,11]
     	char = data[idx]
         print(char)
     

Practice questions

1. The for loop outputs each character of message = "伤情最是晚凉天，憔悴厮人不堪言".

   message = "伤情最是晚凉天，憔悴厮人不堪言"
   for item in message:
       print(item)
   

2. for loop + range realizes outputting each character in message = "伤情最是晚凉天，憔悴厮人不堪言" in reverse order.

   message = "伤情最是晚凉天，憔悴厮人不堪言"
   
   for i in range(len(message)-1, -1, -1):
       print(message[i])
   

3. Let the user input a piece of text and count the number of times "wave" appears in the output text.

   text = input(">>>")
   count = 0
   for item in text:
       if item == "浪":
           count += 1
           
   data = "浪出现的次数：{}次".format(count)
   print(data)
   

4. Write code to implement:

   • Prompts the user to enter content, which includes: as8dfa9784adfasdf sofa cushion
   • Extract the number from the user input: 89784
   • Convert the extracted number to an integer, and then convert the integer to a binary string.
   • Remove the 0b in front of the binary string.
   • Output the binary string after removing 0b.

   text = input(">>>") # abc11uu98f3
   
   char_list = [] # ["1","1","9","8","3"]
   for item in text:
       if item.isdecimal():
           char_list.append(item)
           
   num_string = "".join(char_list) # "11983"
   num_int = int(num_string) # 11983
   bin_string = bin(num_int) # 0b110101010010101
   res = bin_string[2:]
   print(res)
   

   text = input(">>>") # abc11uu98f3
   
   char_list = [] # ["1","1","9","8","3"]
   for item in text:
       if item.isdecimal():
           char_list.append(item)
           
   res = bin(int("".join(char_list)))[2:]//bin(int("".join(char_list)))[2:]
   print(res)
   

5. Query all files in a directory on your own computer and determine whether the file extension is: png or PNG. If so, output it.

   import os//
    #mac系统
   # ['[email protected]', '[email protected]', '[email protected]', 'demo.py', '.idea']
   data_list = os.listdir("/Users/wupeiqi/PycharmProjects/gx_day03")//拿到该目录下所有文件夹和文件，并将其文件名放在列表中
   for file_name in data_list:
       print(file_name)//换行
   
   # win
    import os
    data_list = os.listdir(r"C:\xx\xx\xx")//拿到该目录下所有文件夹和文件，并将其文件名放在列表中
    for file_name in data_list:
        print(file_name) # "字符串"
   

   import os
   
    data_list = os.listdir("/Users/wupeiqi/PycharmProjects/gx_day03")
    for file_name in data_list:
        # print(file_name)  # "字符串"
        if file_name.upper().endswith(".PNG")://文件名变成大写的结尾是否为PNG
            print(file_name)
   

   import os
   
   data_list = os.listdir("/Users/wupeiqi/PycharmProjects/gx_day03")
   for file_name in data_list:
       # text = "中国联通"
       # text[-1]
       # name_list = ["WX20201115-092707@2x","png"]
       # name_list[-1]
       name_list = file_name.split(".")  # [email protected]
       if name_list[-1].upper() == "PNG":
           print(file_name)
   

2. List

A list is an ordered and mutable container whose elements can be of many different data types.

2.1 Definition

data_list = [ 11, 22, "中国俩通", True]

data = []
data.append(11)
data.append(999)

Note: The list is a variable type, and most functions operate on the original list.

2.2 Unique functions

1. addition

   data_list = []
   
   data_lista.append(11)
   data_lista.append("wupeiqi")
   

   hobby_list = []
   while True:
       hobby = input("请输入你的爱好：")
       if hobby.upper() == "Q":
           break
       hobby_list.append(hobby)//list.append()
   

2. Insert, insert the data into that location.

   #              0      1       2      3
   user_list = ["陈清","李阳金","马其坤","刘东"]
   user_list.insert(1,"孟东珏")//插入到索引为1的地方
   
   print(user_list) # ["陈清", "孟东珏", "李阳金","马其坤","刘东"]
   

   user_list = ["李柔","周雪梅","卢慧","孟东珏","陈清","李阳金","马其坤","刘东"]
   
   user_list.insert(0,"孟东珏")
   user_list.insert(0,"卢慧")
   user_list.insert(0,"周雪梅")
   user_list.insert(0,"李柔")
   

   # 案例：排队
   user_list = []
   while True:
       name = input("请输入姓名：")
       if name.upper() == "Q":
           break
   	if name.startswith("刁")://输入名字前有刁放第一位
           user_list.insert(0,name)
   	else:
           user_list.append(name)
   

3. delete (value delete)

   user_list = ["李柔","周雪梅","卢慧","孟东珏","陈清","李阳金","马其坤","刘东"]
   
   user_list.remove("陈清清")//list.remove(删除元素)，删除从左到右的第一个符合要求的元素
   
   # ["李柔","周雪梅","卢慧","孟东珏","李阳金","马其坤","刘东"]
   print(user_list)
   

   Note: When using remove to delete an element of the list, if the element does not exist, an error will be reported.

   user_list = ["李柔","周雪梅","卢慧","孟东珏","陈清","李阳金","马其坤","刘东"]
   if "陈清清" in user_list:
       user_list.remove("陈清清")
   

   # 抽奖小程序
   
   import random
   
   # 1.构造200名员工并存放在列表中。
   user_list = []
   for i in range(1, 201):
       name = "工号-{}".format(i)
       user_list.append(name)
       
   # 2.随机抽取1名员工，发奖金20w
   # 随机去user_list列表中抽取一个数据
   data = random.choice(user_list)//randon.choice()随机抽取一个数据
   print("获得3等奖的是：", data)
   
   # 将用户在列表中删除
   user_list.remove(data)
   
   # 随机去user_list列表中抽取一个数据
   data = random.choice(user_list)
   print("获得2等奖的是：", data)
   

4. Delete(index position)

   user_list = ["李柔","周雪梅","卢慧","孟东珏","陈清","李阳金","马其坤","刘东"]
   
   user_list.pop(1)//根据索引位置删除元素
   
   # ["李柔", "卢慧","孟东珏","陈清","李阳金","马其坤","刘东"]
   print(user_list)
   

   user_list = ["李柔","周雪梅","卢慧","孟东珏","陈清","李阳金","马其坤","刘东"]
   
   user_list.pop()//默认删除尾部元素
   
   #  ["李柔","周雪梅","卢慧","孟东珏","陈清","李阳金","马其坤"]
   print(user_list)
   

   user_list = ["李柔","周雪梅","卢慧","孟东珏","陈清","李阳金","马其坤","刘东"]
   
   # 1.在原列表中删除指定索引位置的值
   # 2.将刚删除的数据获取到并赋值前面的变量。
   data = user_list.pop(1)
   print(data) # "周雪梅"
   print(user_list) # ["李柔", "卢慧","孟东珏","陈清","李阳金","马其坤","刘东"]
   

   # 排队买火车票
   
   # 1.排队买票的人
   user_queue = []
   while True:
       name = input("上海~北京火车票，购买者姓名(Q/q）：")
       if name.upper() == "Q":
           break
       user_queue.append(name)
   
   # 2.放了3张票
   for i in range(3):
       username = user_queue.pop(0)
       message = "恭喜{}，购买成功".format(username)
       print(message)
   
   # 3.通知其他人，无票，请选择其他出行方式
   others = "，".join(user_queue)
   data = "票已售罄，请以下人员选择其他出行方式：{}".format(others)
   print(data)
   

5. clear the list

   user_list = ["李柔","周雪梅","卢慧","孟东珏","陈清","李阳金","马其坤","刘东"]
   
   user_list.clear()//list.clear()
   
   print(user_list) # []
   

6. Sorting list elements

   num_list = [11, 22, 8, 12, 99, 231, 1]
   
   num_list.sort()//排序，默认从小到大
   
   print(num_list)  # [1, 8, 11, 12, 22, 99, 231]
   

   num_list = [11, 22, 8, 12, 99, 231, 1]
   
   num_list.sort(reverse=True)//从大到小
   
   print(num_list)  # [231, 99, 22, 12, 11, 8, 1]
   

   Chinese sorting rules: unicode (understand)

   user_list = ["页子", "青青", "韦神", ]
   
   user_list.sort()
   
   print(user_list)  # ['青青', '韦神', '页子']
   

2.3 Public functions

1. length//list length

   data_list = [11,22,33,44]
   
   res = len(data_list)
   print(res) # 4
   

2. index

   #              0       1      2       3     4     5        6      7
   #                                                ...     -2      -1
   user_list = ["李柔","周雪梅","卢慧","孟东珏","陈清","李阳金","马其坤","刘东"]
   
   # 获取值
   user_list[0]
   user_list[2]
   user_list[  len(user_list)-1   ]
   user_list[-1]
   
   # 修改//列表可以修改，所以利用索引可以修改
   user_list[1] = "马冬梅"
   print(user_list) # ["李柔","马冬梅","卢慧","孟东珏","陈清","李阳金","马其坤","刘东"]
   
   # 删除
   del user_list[5]
   print(user_list) #  ["李柔","周雪梅","卢慧","孟东珏","陈清",马其坤","刘东"]
   

3. slice

   user_list = ["李柔","周雪梅","卢慧","孟东珏","陈清","李阳金","马其坤","刘东"]
   
   # 读取一部分
   user_list[0:4]  #  ["李柔","周雪梅","卢慧","孟东珏"]
   user_list[0:-1]  #  ["李柔","周雪梅","卢慧","孟东珏","陈清","李阳金","马其坤"]
   user_list[2:]  # ["卢慧","孟东珏","陈清","李阳金","马其坤","刘东"]
   user_list[:]  # ["李柔","周雪梅","卢慧","孟东珏","陈清","李阳金","马其坤","刘东"]
   
   # 修改一部分
   user_list = ["李柔", "周雪梅", "卢慧", "孟东珏", "陈清", "李阳金", "马其坤", "刘东"]
   user_list[0:2] = [11, 22, 33, 44]//二换四
   # [11, 22, 33, 44, '卢慧', '孟东珏', '陈清', '李阳金', '马其坤', '刘东']
   print(user_list)
   
   # 删除
   user_list = ["李柔", "周雪梅", "卢慧", "孟东珏", "陈清", "李阳金", "马其坤", "刘东"]
   del user_list[2:4]
   # ['李柔', '周雪梅', '陈清', '李阳金', '马其坤', '刘东']
   print(user_list)
   

4. for loop

   user_list = ["李柔","周雪梅","卢慧","孟东珏","陈清","李阳金","马其坤","刘东"]
   for item in user_list:
       print(item)
   

   user_list = ["李柔","周雪梅","卢慧","孟东珏","陈清","李阳金","马其坤","刘东"]
   
   for i in range(len(user_list)):
       print(i)
       print( user_list[i]  )
   

   user_list = ["李柔", "周雪梅", "卢慧", "孟东珏", "陈清", "李阳金", "马其坤", "刘东"]
   
   for i in range(len(user_list)):
       data = "{}-{}".format(i, user_list[i])
       print(data)
   

2.4 Nesting

A list is a "container", and many things can be placed in the container.

data_list = [11,22,"武沛齐",["中国联通","中国移动"],666, True]

data_list = [
    "梁吉宁",
    "赵建先",
    'root',
    [999,888,777,666],
    'admin',
    666,
	["周杰伦","刘欢","林俊杰","王一博"],
    ["刘翔","周琦",["姚明","王治郅","巴蒂尔"],"赵继伟"],
]

res = data_list[2].upper()//生成新的值赋给res
print(data_list) # 中的root是小写的。
print(res) # ROOT


# 取值
data_list[1] 			"赵建先"
data_list[1][-1]   		"先"
data_list[-1][2][-2]	"王治郅"

# 操作
data_list[0] = "李柔"
data_list[3][-1] = "666"

data_list[4][0] = "A"  # 报错？  admin-> Admin//报错，字符串无法修改
print(data_list)

# 操作
data_list.append(123)
data_list[-1].append("大侄子")//不会报错，把元素加在"赵继伟"后面
data_list[-1][2].append("大侄子")//"巴蒂尔"后面
# 列表是一个可变类型，列表中的常见功能是对列表本身进行操作。

Practice questions

1. User registration, loop prompts the user to enter the user name and password, and terminates if Q or q is entered when the user name is entered.

   user_list = [ ["用户名A","密码A"] , ["用户名A","密码A"], ["用户名A","密码A"]  ]
   

   user_list = []
   
   while True:
       user = input(">>>")
       if user.uppper() == 'Q':
           break
   	pwd = input(">>>")
       
       item = [ user, pwd ]
       user_list.append(item)
   

2. Loop out product information

   goods = [
       ["飞机",3000],
       ["迫击炮",1000],
       ["AK47",300],
       ["m6",600],
   ]
   
   for i in range(len(goods)):
       message = "{} {}".format(i, goods[i][0] )
       print(message)
   

   # 输出
   0 飞机
   1 迫击炮
   2 AK47
   3 m6
   

3. The product information is output in a loop. The user enters the serial number. The product information is obtained according to the serial number entered by the user and output. The format is as follows:

   您选择的商品是xx,价格是xx。
   

   goods = [
       ["飞机", 3000],
       ["迫击炮", 1000],
       ["AK47", 300],
       ["m6", 600],
   ]
   
   # 1.展示商品信息
   for i in range(len(goods)):
       message = "{} {}".format(i, goods[i][0])
       print(message)
   
   # 2.用户选择
   choice = input("请选择：")
   if choice.isdecimal():
       # 整型
       choice = int(choice)
       # 范围
       if choice >= 0 and choice < len(goods):
           data_info = goods[choice]
           message = "您选择的商品是{},价格是{}。".format(data_info[0], data_info[1])
           print(message)
       else:
           print("序号输入不合法")
   else:
       print("输入必须是整数")
   
   

   goods = [
       ["飞机", 3000],
       ["迫击炮", 1000],
       ["AK47", 300],
       ["m6", 600],
   ]
   
   # 1.展示商品信息
   for i in range(len(goods)):
       message = "{} {}".format(i, goods[i][0])
       print(message)
   
   # 2.用户选择
   choice = input("请选择：")
   if choice.isdecimal():
       # 整型
       choice = int(choice)
       # 范围
       if 0 <= choice < len(goods):
           data_info = goods[choice]
           message = "您选择的商品是{},价格是{}。".format(data_info[0], data_info[1])
           print(message)
       else:
           print("序号输入不合法")
   else:
       print("输入必须是整数")
   

4. Here are some sensitive words for you

key_list = ["日本","台湾","美国","新疆"]

text = input("请输入评论：")

# 将评论的内容中出现的关键字全部替换成 **

key_list = ["日本","台湾","美国","新疆"]
text = input("请输入评论：") # "你美国和日本人的混血"
for key in key_list:
    text = text.replace(key,"**")//替换，replace
print(text)

3. Tuple

A list is an ordered and mutable container whose elements can be of many different data types.

A tuple is an ordered and immutable container whose elements can be of many different data types.

data = []
data.append(11)
data.append(234)

# 定义了一个元组，元组中有三个元素。不能删，不能改，不能添加
data = (11,22,33)

3.1 Definition

v1 = (11,22,33)
v2 = (11,22,True,"武沛齐")
v3 = (11,22,True,(55,66), "武沛齐",[11,22,33,44])

The number of tuples cannot be modified; the elements of a tuple cannot be replaced with other values.

Note: error-prone points in tuples.

v1 = (11,22)   # 正确，元组
v2 = (33,44,)  # 正确，元组,逗号可有可无

v3 = (666)    # v3 = 666
v4 = (666,)   # v4 = 元组，只有一个元素666

If there is only one element in the tuple and there is no comma at the end, it is not a tuple, but the value after removing the parentheses.

1. 比较一下三个值的区别：
	v1 = (1)
    v2 = 1 
    v3 = (1,)
    
2.比较一下三个值的区别：
	v1 = ( (1),(2),(3) )
	v2 = ( 1, 2, 3 )
	v3 = ( (1,), (2,), (3,) )

3.2 Unique functions

none

3.3 Public functions

1. length

   v1 = (11,22,True,"武沛齐")
   
   res = len(v1)
   print(res) # 4
   

2. Index (read only)

   v1 = (11,22,True,"武沛齐")
   
   v1[0]
   v1[2]
   v1[-1]
   

3. Slicing //One point copies a new value

   v1 = (11,22,True,"武沛齐")
   
   v2 = v1[1:3] 
   print(v2) # (22,True)
   
   v3 = v1[1:] 
   print(v3) # (22,True,"武沛齐")
   

4. for loop

   v1 = (11,22,True,"武沛齐")
   for item in v1:
       print(item)
   

   v1 = (11,22,True,"武沛齐")
   for i in range(len(v1)):
       print(i)
       print( v1[i] )
   

3.4 Nesting

data = (
	11,
    22,
    True,
    ("陆梅","吴国锋",[1,2,3,4])
    "武沛齐",
    ["陈清","马其坤","李冉"]
)

data[-2]   # ""武沛齐""
data[-3][0] # "陆梅"
data[-3][-1][0] # 1

# 元组的元素不可以被替换，元素个数也不允许修改。
data[0] = 123  # 报错
data[-1] = 666 # 报错

data[-1][0] = "张电摩"  # 正确，整体未被替换

Practice questions

1. First there is a tuple, which stores some data, for example:

   data = ("京A99110","沪B88776","黑A88776",...)
   
   # 1.获取所有京牌的车牌并放到一个列表中。
   
   # 2.输出列表；再输出京牌的个数。
   

   data = ("京A99110", "沪B88776", "黑A88776", "京A11111","京A111331")
   result = []
   for item in data:
       if item.startswith("京"):
           result.append(item)
   
   print(result)
   print(len(result))
   

2. Create a deck of playing cards (excluding kings and kings)

   color_list = ["红桃","黑桃","方片","梅花"]
   
   # num_list = range(1,14)
   num_list = [1,2,3,4,5,6,7,8,9,10,11,12,13]
   
   # 获取一副扑克牌
   # result = [ ("红桃",1),("红桃",2)....,("黑桃",1)..("梅花",13)  ]
   

   color_list = ["红桃", "黑桃", "方片", "梅花"]
   
   num_list = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]
   
   result = []
   for color in color_list:
       # print(color)  # color="黑桃"
       for num in num_list:
           item = (color, num)
           result.append(item)
   
   print(result)