> str=[1,2,3,4,5,2,6]
> str.remove(2)
> str

> str=[0,1,2,3,4,5,6]
> str.pop(1) #pop删除时会返回被删除的元素
> str

> str2=['abc','bcd','dce']
> str2.pop(2)
'dce'
> str2

> str=[1,2,3,4,5,2,6]
> del str[1]
> str

> str2=['abc','bcd','dce']
> del str2[1]
> str2

> str=[0,1,2,3,4,5,6]
> del str[2:4] #删除从第2个元素开始，到第4个为止的元素(但是不包括尾部元素)
> str

> str=[0,1,2,3,4,5,6]
> del str
> str #删除后，找不到对象

s1 = (1, 2, 3, 4, 5, 6)
s2 = (2, 3, 5)
s3 = []
for i in s1:
  if i not in s2:
    s3.append(i)
print('s1_1:', s1)
s1 = s3
print('s2:', s2)
print('s3:', s3)
print('s1_2:', s1)