1. Create:
Create a list s1 s1=[1,2,3,,4,'hui','ggg','aaa']
Create empty list s2 s2=[]
2. Inquiry
name=["shan","gaohui","aaa","bbb",1,2,5,6,7,5,9,3]
1) If you query from the front, the index starts from 0
Example: Find shan: name[0]
2) If you query from the back, the index starts from -1
Example: Find 3: name[-1]
3) Check the index value
Example: Find the index value of aaa: name.index(aaa) #If there are multiple aaa, only the index value of the first aaa will be displayed.
4) Check the number in the list
Example: Find how many aaa are in the list: name.count(aaa)
3. Slicing method: don't care about the end
name=["shan","gaohui","aaa","bbb",1,2,5,6,7,5,9,3]
1) Output the first 4:
print(name[0:4]) 输出为："shan","gaohui","aaa","bbb"
2) Output the last 5:
The output of print(name[-5:]) is: [6,7,5,9,3] ##The last 0 can be omitted, so the first 4 of the above output can also be written as name[:4]
3) Output the first 4 bits and output one bit in the interval:
The output of print(name[0:4:2]) is: ["shanshan", "aaa"] #If every 2 bits is output, the colon after 4 is 3 (this 3 is called the step size)
4. Add and Append
name=["shan","gaohui","aaa","bbb",1,2,5,6,7,5,9,3]
1) Add content xxx at the end
name.append(“xxx”)
2) Add a "ccc" before aaa
name.insert(2(index),"ccc) The position to insert is one position before this index
5. Modification
name=["shan","gaohui","aaa","bbb",1,2,5,6,7,5,9,3]
1) Change "aaa" to "ccc"
name[2]="ccc"
2) Change "aaa" and "bbb" to "Jack Liu"
name[2:4]="Jack Liu" The output is: ['shanshan', 'gaohui', 'J', 'a', 'c', 'k', ' ', 'L', 'i', 'u', 1, 2, 5, 6, 7, 5, 9, 3]
6. Delete
1) name.pop(): delete the last one in the list
2) name.remove("content in the list") ##If there are multiple defaults, delete the first one
3) del name[2] ##Index in brackets del name[index:index]
7. Loop
for i in [] #list or for i in range[0,10]
Difference between for and while loop:
for cannot be defined as an infinite loop while can be defined as an infinite loop
8. Sort
name=["shan","gaohui","aaa","bbb",1,2,5,6,7,5,9,3]
name.sort() sort by ascll code
n.reverse() reverse
9. Splicing
name=[1,2,3,4,5]
name2=[1,2,4,5,6]
Method 1: name+name2
Method 2: name=name.extend(name2)