怎么删除里表中的前几个元素

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

>>> str.remove(2)

>>> str

[1, 3, 4, 5, 2, 6]

>>> 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

[0, 2, 3, 4, 5, 6]

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

>>> str2.pop(2)

'dce'

>>> str2

['abc', 'bcd']

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

>>> del str[1]

>>> str

[1, 3, 4, 5, 2, 6]

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

>>> del str2[1]

>>> str2

['abc', 'dce']

>>> 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

[0, 1, 4, 5, 6]