It's all basic knowledge, you will forget it if you don't use it for a long time, learn the new by reviewing the past, and come to learn again. I believe that many people will use it in programming or thinking about some program processing, such as interviews 
(please correct me if there is something wrong~
1. List definition
A list is an ordered and mutable collection. In Python, lists are denoted by square brackets. The content in the list can be of any type and can be repeated.
li = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 1, 1, 2, 3]
print(li)
['A', 'B', 'C', 'D', 'E', 'F', 'G', 1, 1, 2, 3]2. Add data to the list
1, add append method
li = ['A', 'B', 'C']
li.append('E') # 一次只能添加一个元素，并且只能在列表最后
print(li)
['A', 'B', 'C', 'E']2. Insert the insert method, which is more flexible than append, specify the index bit, and note that the index starts from 0
li = ['A', 'B', 'C']
li.insert(0, 'M') # 在首位插入M,两个参数
print(li)
['M', 'A', 'B', 'C']3. Delete the data in the list
1. pop-up method
li = ['A', 'B', 'C']
li.pop() # 根据索引进行删除，默认删除最后一个元素,一次只能删除一个
print(li)
['A', 'B']
Delete the data at the specified location
li = ['A', 'B', 'C']
li.pop(0) # 删除第一位
print(li)
['B', 'C']2. Remove the remove method
li = ['A', 'B', 'C']
li.remove('B') # 删除列表中的值,一次只能删除一个
print(li)
['A', 'C']3. Operation statement del
li = ['A', 'B', 'C']
del li[0] #删指定索引的元素，需要注意是del是一种操作语句
print(li)
['B', 'C']4. Index (ie subscript)
li = ['A', 'B', 'C']
print(li[0]) # 获取首位
print(li[-1]) # 获取末尾
A
C5. Slicing, regardless of the head and the tail
li = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 1, 1, 2, 3]
print(li[0:2]) # 获取前两位
['A', 'B']
print(li[:]) # 获取全部
['A', 'B', 'C', 'D', 'E', 'F', 'G', 1, 1, 2, 3]
print(li[4:]) # 获取第5位到尾部
['E', 'F', 'G', 1, 1, 2, 3]
print(li[-3:-1]) # 获取倒数第3到倒数第2
[1, 2]
Six, jumping, involving step size
The main point is to find the index bit, the step size is positive, and the step size is negative, and the step size is reversed
li = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 1, 1, 2, 3]
print(li[1:5:3]) # 从第2位到第6位，隔2个获取
['B', 'E']
print(li[0:5:2]) # 从开头到第6位，隔1个获取
['A', 'C', 'E']
print(li[5:0:-2]) # 从第6位开始，隔1个倒着获取
['F', 'D', 'B']Seven, commonly used list operators
1. copy *
li = ['A', 'B']
print(li * 2) # 复制列表中的值追加到列表
['A', 'B', 'A', 'B']2. Stitching +
li = ['A', 'B']
li2 = ['C', 'D']
print(li + li2) # 两个列表拼接
['A', 'B', 'C', 'D']8. Count the number of occurrences of an element in the list
li = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 1, 1, 2, 3]
print(li.count('A')) # 统计元素A出现的次数
print(li.count(1)) # 统计元素1出现的次数
1
2Nine, find elements
If there are duplicate elements in the list, the index method only finds the first occurrence of the index bit
li = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 1, 1, 2, 3]
print(li.index('A')) # 查找元素A首次出现的索引位置
print(li.index(1)) # 查找元素1首次出现的索引位置
0
710. Reverse the list
li = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 1, 1, 2, 3]
li.reverse() # 反转列表元素
print(li)
[3, 2, 1, 1, 'G', 'F', 'E', 'D', 'C', 'B', 'A']11. List sorting
Only valid for full values, otherwise an error will be reported
li = [1, 5, 2, 99, 6, 44, 66, 3, 34]
li.sort() # 默认对列表数据进行从小到大排序
print(li)
[1, 2, 3, 5, 6, 34, 44, 66, 99]
li.sort(reverse=True) # 对列表数据进行从大到小排序
[99, 66, 44, 34, 6, 5, 3, 2, 1]
#根据对列表元素反转的规律，从大到小排序也可以先sort后再reverse
#li.sort()
#li.reverse()12. Copy list
1. Shallow copy, changing one will affect the other
#浅拷贝
l = ['A', 'B']
k = l
print(k)
l.append('C')
print(l)
print(k) # 对l列表进行操作会同步影响k列表值
['A', 'B']
['A', 'B', 'C']
['A', 'B', 'C']2. Deep copy, changing one will not affect the other
# 深拷贝
m = ['A', 'B']
n = m[:]
print(n)
m.append('C')
print(m)
print(n) # 对m列表进行操作不影响n列表值
['A', 'B']
['A', 'B', 'C']
['A', 'B']3. Copy function, changing one will not affect the other
m = ['A', 'B']
n = m.copy()
print(n)
m.append('C')
print(n)
['A', 'B']
['A', 'B']4. The built-in method list, the essence can be understood as converting to a list, changing one will not affect the other
m = ['A', 'B']
n = list(m)
print(n)
m.append('C')
print(n)
['A', 'B']
['A', 'B']