python增删改查（四）

###增删改查
names = ["zhangding","wangxu","wudong","cheng"]

#增
names.append("zhangzhengxin")  #增加
print(names)
names.insert(,"liu")  #插入
names.insert(,"shun")
print(names)

#删
#names.remove("liu")
#del names[]
print(names.pop())
print(names)

#改
names[] = "王旭"
print(names[::])

#查
print(names[-])
print(names[:])
print(names[-:]) #get the  element
print(names[:])  #get the first  element
print(names.index("王旭"))   #取元素的下标

#两个列表的合并
n2=[","B","*"]
names.extend(n2)
print(names,n2)

names.reverse()  #旋转
print(names)

names.sort()   #排序
print(names)

n3 = names.copy() #copy
n4 = names
print((n3),id(names),id(n3))
print(n4,id(names),id(n4))

names.pop()
print("------------")
print(n3,id(names),id(n3))
print(n4,id(names),id(n4))