列表和元组的一些笔记

#列表
# 1. 列表格式
# 2. 列表中可以嵌套任何类型
li = [1,2,3,["分割线",23,45],"sljfg",True,(23,),{"jiwei":23},] #列表中的元素可以是 数字，字符串,列表，布尔值,元组，字典
print(li)
# 3索引,索引从0开始计数，
print(li[0])#li[0]对应li中的第一个元素1
#4 切片，输出后还是列表
print(li[1:-1])#其中-1是右边第一个元素，[1:-1]是切片从左边第二个元素到右边第一个元素之间元素
#5for循环
li = [1,2,3,["分割线",23,45],"sljfg",True,(23,),{"jiwei":23},]
for item in li:
    print(item)

#6 索引
li = [1,2,3,["分割线",23,45],"sljfg",True,(23,),{"jiwei":23},]
li[0] = 10 #可以数字和改成其他类型
print(li)
li[1] = [2,3,456]

# 删除
del li[1]
print(li)

#7 切片
li = [1,2,3,["分割线",23,45],"sljfg",True,(23,),{"jiwei":23},]
li[2:4] = [234,3455]
print(li)
# 删除某段切片
del li[1:3]
print(li)

# 8in 的操作
li = [1,2,3,["分割线",23,45],"sljfg",True,(23,),{"jiwei":23},]
w ="sljfg" in li
print(w)

# 9字符串可以直接转换成列表
b = "suogiwoehgoiahgiai"
new_list = list(b)
print(new_list)
# 列表转换成字符串
li = [11,22,33,"123","alex"]
r = str(li) # 将列表改变成字符串'[11,22,33,"123","alex"]'
print(r)
# 将字符串拼接打印
s = ""
for i in li:
    s = s + str(i)
print(s)

 元组

# 1. 书写格式
# tu = (111,"alex",(11,22),[(33,44)],True,33,44,)
# 一般写元组的时候，推荐在最后加入 ,
# 元素不可被修改，不能被增加或者删除
# 2. 索引# v = tu[0]
# print("索引:",v)

# 3. 切片
# v = tu[0:2]
# print("切片:",v)

# 4. 可以被for循环，可迭代对象
# for item in tu:
#     print(item)

# 5. 转换
# s = "asdfasdf0"
# li = ["asdf","asdfasdf"]
# tu = ("asdf","asdf")
#
# v = tuple(s)
# print("字符串转换元组：",v)

# v = tuple(li)
# print("列表转换元组：",v)

# v = list(tu)
# print("元组转换字符：",v)

# v = "_".join(tu)
# print(v)

# li = ["asdf","asdfasdf"]
# li.extend((11,22,33,))
# print("extend(在列表末尾添加元素：",li)

# 6.元组的一级元素不可修改/删除/增加
# tu = (111,"alex",(11,22),[(33,44)],True,33,44,)
# # 元组，有序。
# # v = tu[3][0][0]
# # print("查找元组中多级子元素：",v)
# # v=tu[3]
# # print(v)
# tu[3][0] = 567
# print(tu)

字典

# 字典
# dic = {
#     "k1": 'v1',
#     "k2": 'v2'
# }
# 1 根据序列，创建字典，并指定统一的值
# v = dict.fromkeys(["k1",123,"999"],123)
# print("fromkeys()可以对多个键统一赋值：",v)

# 2 根据Key获取值，key不存在时，可以指定默认值（None）
# dic = {
#     "k1": 'v1',
#     "k2": 'v2'
# }
# v = dic['k11111']
# print("根据Key获取值，key不存在时报错：",v)
# v = dic.get('k1',111111)
# print("根据Key获取值，key不存在时get返回默认值（None）：",v)

# 3 删除并获取值
# dic = {
#     "k1": 'v1',
#     "k2": 'v2'
# }
# v = dic.pop('k1',90)
# print("删除并获取值:",dic,v)
# k,v = dic.popitem()
# print("删除并获取值:",dic,k,v)

# 4 设置值，
# 已存在，不设置，获取当前key对应的值
# 不存在，设置，获取当前key对应的值
# dic = {
#     "k1": 'v1',
#     "k2": 'v2'
# }
# v = dic.setdefault('k1111','123')
# print(dic,v)

# 5 更新
# dic = {
#     "k1": 'v1',
#     "k2": 'v2'
# }
# dic.update({'k1': '111111','k3': 123})
# print(" 更新字典中的元素，相同的替换值，不同的添加：",dic)
# dic.update(k1=123,k3=345,k5="asdf")
# print(" 更新字典中的元素，相同的替换值，不同的添加：",dic)

# 6 keys()  7 values()   8 items()   get   update
##########



# 1、基本结构
# info = {
#     "k1": "v1", # 键值对
#     "k2": "v2"
# }
#### 2 字典的value可以是任何值
# info = {
#     "k1": 18,
#     "k2": True,
#     "k3": [
#         11,
#         [],
#         (),
#         22,
#         33,
#         {
#             'kk1': 'vv1',
#             'kk2': 'vv2',
#             'kk3': (11,22),
#         }
#     ],
#     "k4": (11,22,33,44)
# }
# print(info)

####  3 列表、字典不能作为字典的key
# info ={
#     1: 'asdf',
#     "k1": 'asdf',
#     False: "123",
#     # [11,22]: 123
#     (11,22): 123,
#     # {'k1':'v1'}: 123
#
# }
# print(info)

# 4 字典无序

# info = {
#     "k0":23,
#     "k1": 18,
#     "k2": True,
#     "k3": [
#         11,
#         [],
#         (),
#         22,
#         33,
#         {
#             'kk1': 'vv1',
#             'kk2': 'vv2',
#             'kk3': (11,22),
#         }
#     ],
#     "k4": (11,22,33,44)
# }
# print("字典的排列无序使用id可以明显看到：",id(info))


# 5、索引方式找到指定元素
# info = {
#     "k10":23,
#     "k1": 18,
#     2: True,
#     "k3": [
#         11,
#         [],
#         (),
#         22,
#         33,
#         {
#             'kk1': 'vv1',
#             'kk2': 'vv2',
#             'kk3': (11,22),
#         }
#     ],
#     "k4": (11,22,33,44)
# }
# v = info['k1']
# print(v)
# v = info[2]
# print(v)
# v = info['k3'][5]['kk3'][0]
# print("查找指定元素",v)

# 6 字典支持 del 删除
# info = {
#     "k1": 18,
#     2: True,
#     "k3": [
#         11,
#         [],
#         (),
#         22,
#         33,
#         {
#             'kk1': 'vv1',
#             'kk2': 'vv2',
#             'kk3': (11,22),
#         }
#     ],
#     "k4": (11,22,33,44)
# }
# del info['k1']
# print("字典支持删除某个键值对：",info)
# del info['k3'][5]['kk1']
# print("字典支持删除多级子元素：",info)

# 7 for循环
# dict
# info = {
#     "k1": 18,
#     2: True,
#     "k3": [
#         11,
#         [],
#         (),
#         22,
#         33,
#         {
#             'kk1': 'vv1',
#             'kk2': 'vv2',
#             'kk3': (11,22),
#         }
#     ],
#     "k4": (11,22,33,44)
# }
# for item in info:
#     print("info输出所有键的key：",item)
#
# for item in info.keys():
#     print("info.keys()输出所有键的key：",item)
#
# for item in info.values():
#     print("info.values()输出所有value：",item)
#
# for item in info.keys():
#     print(item,info[item])
#
# for k,v in info.items():
#     print("输出键值对;",k,v)