Python list additions and deletions

List additions and deletions
First, Increase: append (), insert () method
1.append () Method: Add an element at the end
#szz = [' ab ', ' jhj ', ' nhy ']
#szz. Append (' msr ')
2.insert () Method: Add elements or lists at the specified location
#szz = [' ab ', ' jhj ', ' nhy ']
#szz1 = [' msr ', ' Mike ']
#szz. Insert (0, ' Mark ')
#szz. Insert (0,SZZ1)
Second, delete: Del, pop (), remove (), clear ()
1.del: You can delete the specified value of the underlying
#del Szz[1]  #删除下标为1的值
2.pop () method:#默认从列表的末尾删除, you can also delete the specified value

Szz.pop ()

The query list can be labeled and sliced
#2 (1) Subscript value, starting from 0
#2 (2) Slice: Gu Tou regardless of tail, and the slice subscript operation is also used for string
"""
names = [' Mike ', ' Mark ', ' Candice ', ' Laular '] #定义列表
info = ' ABCDEFGHIJKLMN '
Num_list = List (range (1,10)) #range生成一个长度为10的
Print (names[2]) #读取列表的值
Print (Names[1:3]) #通过切片方式取值, the slice is Gu Tou regardless of the tail, printing results: [' Mark ', ' Candice ']
Print (names[1:]) #取下标后面所有的值, printing results: [' Mark ', ' Candice ', ' Laular ']
Print (Names[:3]) #取下标前面所有的值, printing results: [' Mike ', ' Mark ', ' Candice ']
Print (names[:]) #取所有的值, printing results: [' Mike ', ' Mark ', ' Candice ', ' Laular ']
Print (Names[-1]) #取最后一个值, printing results: laular
Print (Names[:1:2]) #隔几位取一次, the default is not to write a step of 1, that is, take one step at a time, the result is to remove the value before the Mark 1, take a [' Mike '] 2 bits
Print (Num_list[::-1]) #从后往前取值 with a step size of 1
Print (num_list)
Print (Info[1:7])
"""



#修改
#szz [0] = ' zzj '
#print (SZZ) #打印结果: [' zzj ', ' ab ', ' jhj ', ' nhy ', ' zxf ']
#删除
#del
#del Szz[1] #删除指定下标的值
#print (SZZ)
#内置方法pop ()
#szz. Pop ()
#print (SZZ)
#szz. Pop (2)

#remove, delete the specified value instead of the subscript
#szz. Remove (' jhj ')
#print (SZZ)
#clear () #清空
#szz. Clear ()
#index, gets the subscript for the specified element
#szz. Index (' jhj ')
#count, gets the number of times the specified element
#szz. Count (' MSR ')
#extend, merge the list, modify the value of the original list
#szz. Extend (SZZ1)
#sort排序, by default ascending from small to large row, descending row add: reverse=true, reverse return meaning
"" "#sort只是一个方法, no return value, so cannot print
Numbs = [12,425,334,32]
Numbs.sort (Reverse=true)
Print (numbs)
"""
#元组的值, can not be changed, is an unreachable list, want to change must first turn to list
#元祖只有count和index方法
Names = (' Mike ', ' Mark ', ' Candice ', ' laular ', ' Mark ', ' msr ')
Print (Names.count (' Mark '))
Print (Names.index (' msr '))


#3. Dictionaries:

Python list additions and deletions