【Python基础】lpthw - Exercise 38 列表的操作

　　1.列表和字符串操作的混合练习

 ten_things = "apples  oranges crows telephone light sugar"

 print("Wait there are not 10 things in that list. Let's fix it.")

 stuff = ten_things.split()
 more_stuff = ["day","night","song","frisbee","corn","banana","girl","boy"]

 while len(stuff) != 10:
     next_one = more_stuff.pop()
     print("Adding:",next_one)
     stuff.append(next_one)
     print(f"There are {len(stuff)} items now.")

 print("There we go:",stuff)

 print("Let's do some things with stuff")

 print(stuff[1])
 print(stuff[-1])
 print(stuff.pop())
 print(' '.join(stuff))
 print('#'.join(stuff[3:5]))

　　输出

Wait there are not 10 things in that list. Let's fix it.
Adding: boy
There are 7 items now.
Adding: girl
There are 8 items now.
Adding: banana
There are 9 items now.
Adding: corn
There are 10 items now.
There we go: ['apples', 'oranges', 'crows', 'telephone', 'light', 'sugar', 'boy', 'girl', 'banana', 'corn']
Let's do some things with stuff
oranges
corn
corn
apples oranges crows telephone light sugar boy girl banana
telephone#light

　　2. 列表的索引和操作

　　参考：聊聊python中的细节--左闭右开区间

　　python在设计索引下标的时候都是采用左闭右开区间的形式，是个值得注意的小细节。

 list = ['a','b','c','d']
 x1 = list[0]      # x1 = a
 x2 = list[-1]     # x2 = d 此时 list = ['a','b','c','d']
 x3 = list.pop()  # x3 = d 此时 list = ['a','b','c']
 x4 = list[1:2]    # x4 = b 注意python中索引时[]为左闭右开区间

　　list.pop()表示取出列表最后一个元素返回给当前被赋值的变量。

　　3. str.join(sequence)

　　返回被str连接的sequence序列，如

 str = "-"
 sequence = ["a","b","c"]
 print(str.join(sequence))

　　输出为

　　a-b-c

　　一般sequence是一个列表，如果它是一个字符串，则将字符串中每个字符视为一个元素并用str去连接它们，如

 str = "-"
 sequence = "test"
 print(str.join(sequence))

　　输出为

　　t-e-s-t

　　4.进一步理解python的列表（作为一种常见的数据结构）

　　有序；

　　可随机访问，也可线性访问（使用索引）；

　　查找时需要依次检索

　　5.巩固练习-概念理解

　　面向对象编程，object oriented programming（OOP）

　　python中的类（class）

　　函数式编程，functional programming