Common Operations on Python Lists
1. Create a list
animals=['dog','cat','lion','rat',2022]
#也可以是：
animals=list['dog','cat','lion','rat',2022]
# 空列表
lst=list()
lst=[]
2. The index of the list
Access elements, subscript value range: [0, n-1] and [-n,-1], 0 to n-1 is the first element counting backwards, -1 to -n is the last start Elements count forward:
print('最后一个元素是：',animals[-1])
print('第一个元素是：',animals[0])
print('按值查找下标：',animals.index(2022))
result:
最后一个元素是： 2022
第一个元素是： dog
按值查找下标： 4
3. Modify the elements of the list:
print('修改前：',animals)
animals[3]='mouse'
print('修改索引为3的元素后：',animals)
result:
修改前： ['dog', 'cat', 'lion', 'rat', 2022]
修改索引为3的元素后： ['dog', 'cat', 'lion', 'mouse', 2022]
4. Add elements to the list:
animals.append('bird')#在末尾添加元素
animals.insert(3,'panda')#在索引为3的位置插入元素
print('添加元素后：',animals)
result:
添加元素后： ['dog', 'cat', 'lion', 'panda', 'mouse', 2022, 'bird']
5. Delete elements of the list:
del statement:
del animals[0]
print('删除了列表索引为0的元素后：',animals)
result:
删除了列表索引为0的元素后： ['cat', 'lion', 'panda', 'mouse', 2022, 'bird']
pop() method:
The pop() method is used to pop up the elements at the end of the list and can be received. Adding an index in parentheses can also pop up elements at any position
poped_animal=animals.pop()
print('弹出了末尾的元素后：',animals)
print('被弹出的元素',poped_animal)
result:
弹出了末尾的元素后： ['cat', 'lion', 'panda', 'mouse', 2022]
被弹出的元素 bird
The remove() method to remove by value:
animals.remove(2022)
print('移除后：',animals)
result:
移除后： ['cat', 'lion', 'panda', 'mouse']
6. Sort the list:
animals.sort()
print('按照字母顺序排序后：',animals)
animals.sort(reverse=True)
print('按照字母顺序反向排序后：',animals)
print('用sorted()临时排序：',sorted(animals))
print(animals)
result:
按照字母顺序排序后： ['cat', 'lion', 'mouse', 'panda']
按照字母顺序反向排序后： ['panda', 'mouse', 'lion', 'cat']
用sorted()临时排序： ['cat', 'lion', 'mouse', 'panda']
['panda', 'mouse', 'lion', 'cat']
7. Slicing of lists:
print('切片前：',animals)
print('[开始下标:结束下标:步长]：',animals[1:3:1])
result:
切片前： ['panda', 'mouse', 'lion', 'cat']
[开始下标:结束下标:步长]： ['mouse', 'lion']
8. Some operations on the list of numbers:
numbers=list(range(0,24,3))
print(numbers)
print('最大值：',max(numbers))
print('最小值：',min(numbers))
print('求和：',sum(numbers))
result:
[0, 3, 6, 9, 12, 15, 18, 21]
最大值： 21
最小值： 0
求和： 84