list 改 --index -- 切片 --步长 运用

#     改值       for  index
k1 = [1,2,3,4,5,6,7,8,9,]
k1[0] = "nihao"   #  k1[需要更改的位置] = “需要更改的内容”
print(k1)   
#  ['nihao', 2, 3, 4, 5, 6, 7, 8, 9]


#  按照切片改值(迭代着增加)
k1 = [1,2,3,4,5,6,7,8,9,]
k1[:3] = "nihao"   #  k1[需要更改的位置] = “需要更改的元素”
print(k1)   
#   ['n', 'i', 'h', 'a', 'o', 4, 5, 6, 7, 8, 9]


# 按照切片(步长)改值(必须一一对应)
k1 = [1,2,3,4,5,6,7,8,9,]
k1[::2] = 'nihao'  # [star : end :  相隔几个单位取值    ]
print(k1)   
#   ['n', 2, 'i', 4, 'h', 6, 'a', 8, 'o']