python 列表的增删改查与嵌套

Posted 2020-11-22 biyunfeng

列表list的增删改查

# 增
    # lst.append("臭袜子") # 追加,在最后添加内容    *****
    # print(lst)
    # lst.insert(1,"张达") # 插入 #消耗性能        ****
    # print(lst)
    # lst.extend("123")          # 迭代添加       ***
    # print(lst)

# 删
    # lst = [1,2,3,4] # 容器
    # print(lst.pop(0))               # 弹出 默认删除最后一个,pop返回的是被删除的元素,通过索引进行删除
    # print(lst)
    # lst.remove(3)                   # 通过元素名称进行删除
    # print(lst)
    # lst.clear()                     # 清空
    # print(lst)
    # del lst                         # del - 垃圾回收机制 删除整个列表
    # print(lst)

    # del lst[0]                      # 通过索引删除
    # print(lst)

    # lst = [1,2,3,4] # 容器          # 通过切片删除
    # del lst[0:2]
    # print(lst)

    # lst = [1,2,3,4] # 容器          # 通过步长删除
    # del lst[0:4:2]
    # print(lst)

# 改
    # lst = [1,2,3,4,5] # 容器
    # 方法一:
    # lst.pop(1)
    # lst.insert(1,"鬼谷子")
    # print(lst)

    # lst[1] = "郎的诱惑"      *****
    # print(lst)

    # lst[1:-1] = "1"  # 可变长     ****
    # print(lst)

    # lst = [1,2,3,4,5] # 容器
    # lst[1:-1] = "11",'2',"3" # lst[1:-1] = ('11', '2', '3')
    # print(lst)

    # lst = [1,2,3,4,5] # 容器
    # lst[1:-1] = 123,  # lst[1:-1] = (123,)
    # print(lst)

    # lst = [1,2,3,4,5] # 容器
    # lst[1:-1] = "可迭代对象"
    # print(lst)

    # lst = [1,2,3,4,5] # 容器
    # lst[1:-1:2] = "乐蝶"  # 如果步长不为1识,修改的内容长度必须和要要修改的位置一致
    # print(lst)


# 查
    # lst = [12,6,3,4,5]
    # 1.lst[0]
    # for循环

    # for i in lst:
    #     print(i)

# 列表的嵌套 -- 索引
# 元组
# range  -- 切片

列表的嵌套

# lst = [["蔡徐坤",["鸡你太美"],"跳","rap","篮球"],
#        ["鹿晗","小鲜肉","上海堡垒","甜蜜暴击"],
#        ["吴亦凡",["大碗宽面"],"加拿大炮王"],
#        ["周琦","大魔王"],
#        ["岳云鹏","五环","我的天哪","你好骚啊"],
#        ["于谦","抽烟","喝酒","烫头"],
#        ["高圆圆",["我们结婚吧",["倚天屠龙记",["金毛",["谢逊",["张无忌",["灭绝师太",["周芷若",["宋青书",["宋元桥","张三丰"]]]]]]]],"搜索"],
#         ["赵又厅","夜华"]],
#        ["刘涛",["欢乐颂","琅琊榜","还珠格格"]],
#        ["刘亦菲",["小龙女","天龙八部","仙剑","四大名捕"],["过儿","断臂","大雕","大宝剑"]]
#        ]
# 倚天屠龙记
# print(lst[6][1][1][0]) 通过索引找到
# "琅琊榜"
# print(lst[7][1][1])  通过索引找到

# 3.使用while循环和for循环分别打印50以内的偶数
# 4.使用while循环和for循环分别打印50以内的奇数


# count = 0
# lst =list(range(0,51,2))
# while count < len(lst):
#     print(lst[count])
#     count += 1

# for i in range(0,51,2):
#     print(i)

# count = 0
# lst =list(range(1,51,2))
# while count < len(lst):
#     print(lst[count])
#     count += 1

# for i in range(1,51,2):
#     print(i)