列表的相关操作

1. 列表的拼接 (同元组)

lst1 = ["hello","world"]lst2 = ["hello","python"]res = lst1 + lst2 print(res) # ["hello","world","hello","python"]

2. 列表的重复 (同元组)

res = lst1 * 3print(res) # ["hello","world","hello","world","hello","world"]

3. 列表的切片 (同元组)

"""语法 => 列表[::] 完整格式：[开始索引:结束索引:间隔值](1)[开始索引:] 从开始索引截取到列表的最后(2)[:结束索引] 从开头截取到结束索引之前(结束索引-1)(3)[开始索引:结束索引] 从开始索引截取到结束索引之前(结束索引-1)(4)[开始索引:结束索引:间隔值] 从开始索引截取到结束索引之前按照指定的间隔截取列表元素值(5)[:]或[::] 截取所有列表"""lst = ["a", "b", "c", "d", "e", "f", "g"]# (1)[开始索引:] 从开始索引截取到列表的最后res =lst[2:]print(res) # ["c", "d", "e", "f", "g"]# (2)[:结束索引] 从开头截取到结束索引之前(结束索引-1)res =lst[:3]print(res) # ["a", "b", "c"]# (3)[开始索引:结束索引] 从开始索引截取到结束索引之前(结束索引-1)res = lst[3:5]print(res) # ["d", "e"]# (4)[开始索引:结束索引:间隔值] 从开始索引截取到结束索引之前按照指定的间隔截取列表元素值# 正向截取res = lst[::5]print(res) # 0 5 10 ["a", "f"]# 逆向截取res = lst[::-3] # -1 -4 -7print(res) # ["g", "d", "a"]# (5)[:]或[::] 截取所有列表res = lst[:]res = lst[::]print(res) # ["a", "b", "c", "d", "e", "f", "g"]

4. 列表的获取 (同元组)

# 0 1 2lst = [10,20,30]#-3 -2 -1print(lst[-1]) # 30

5. 列表的修改 ( 可切片形式 )

lst = ["孟凡伟","康与众","张宇","赵沈阳","需保障","梁新宇","沈思雨"]# 改单个值lst[1] = "陈璐"print(lst)# 1.改多个值 (如果使用切片进行修改,要求数据必须是Iterable可迭代性数据)lst[1:4] = ["孙悟空","猪八戒","白骨精"] # ["孟凡伟","孙悟空","猪八戒","白骨精","需保障","梁新宇","沈思雨"]# lst[1:4] = 123 # 报错 TypeError: can only assign an iterablelst[1:4] = "你好" # ["孟凡伟","你","好","需保障","梁新宇","沈思雨"]print(lst)# 2.改多个值(带有步长)"""带有步长的切片修改,切出几个元素就修改几个元素,数量要一致."""lst = ["孟凡伟","康与众","张宇","赵沈阳","需保障","梁新宇","沈思雨"]"""0 3 6 """lst[::3] = "abc" # ["a","康与众","张宇","b","需保障","梁新宇","c"]# lst[::3] = "ab" # 报错 ValueErrorprint(lst)

6. 列表的删除 ( 可切片 )

lst = ["孟凡伟","康与众","张宇","赵沈阳","需保障","梁新宇","沈思雨"]# 1.一次删一个# del lst[2]# print(lst) # ["孟凡伟","康与众","赵沈阳","需保障","梁新宇","沈思雨"]# 2.一次删一堆# del lst[1:-1]# print(lst) # ["孟凡伟","沈思雨"]# 3.注意点res = lst[1:-1]del res # 删除的是res这个变量 和 列表无关print(lst)# 额外的注意点: 元组不能修改，但里面的列表元素则是可以修改的tup = (1,2,3,4,[10,11,12])print(tup[-1])tup[-1][-1] = 13print(tup) # (1,2,3,4,[10,11,13])

列表的常用内置方法

增 删 改 查

1.append向列表的末尾添加新的元素

"""功能：向列表的末尾添加新的元素格式：列表.append(值)返回值：None注意：新添加的值在列表的末尾，该函数直接操作原有列表"""lst = ["a"]lst.append("b")print(lst) # ["a", "b"]

2.insert在指定索引之前插入元素

lst = ['a', 'b']# 直接改变原有列表lst.insert(1,"z")print(lst) # ["a", "z", "b"]

3.extend迭代追加所有元素

"""迭代追加的数据是可迭代性数据(容器类型数据,range对象,迭代器)"""lst = ['hello', 'world']# tup = (1,2,3)# lst.extend(tup) # 直接修改原容器 ['hello', 'world',1,2,3]# strvar = "abc"# lst.extend(strvar)lst.extend(range(3))print(lst)

4.pop通过指定索引删除元素,若没有索引移除最后那个 (推荐)

"""功能：通过指定索引删除元素,若没有索引移除最后那个格式：列表.pop(索引)返回值：删除的元素(注意：没有指定索引，默认移除最后一个元素 )"""lst = ["a", "b", "c"]# 不指定下标,默认删除最后一个res = lst.pop()print(res) # cprint(lst) # ["a", "b"]# 指定下标,删除具体某个元素res = lst.pop(1)print(res) # b print(lst)# ["a"]

5.remove通过给予的值来删除,如果多个相同元素,默认删除第一个

"""功能：通过给予的值来删除,如果多个相同元素,默认删除第一个格式：列表.remove(值)返回值：None(注意：如果有索引的情况推荐使用pop,效率高于remove)"""lst = ["曹静怡","王志国","合理","邓鹏","合理"]res = lst.remove("合理")print(res) # Noneprint(lst) # ["曹静怡","王志国","邓鹏","合理"]

6.clear清空列表

lst = ["曹静怡","王志国","合理","邓鹏","合理"]lst.clear()print(lst) # []

6. 其他相关函数

# 列表中没有 find 函数# 1. index 获取某个值在列表中的索引lst = ["曹静怡","王志国","合理","邓鹏","合理","邓鹏辉","邓鹏蓝","合理","邓鹏绿"]res = lst.index("合理") # 2res = lst.index("合理",3) # 4res = lst.index("合理",3,6) # 3 4 5中找# res = lst.index("合理大") # 报错print(res)# 2. count 计算某个元素出现的次数res = lst.count("合理") # 没有范围的概念print(res) # 3# 3. sort 对列表排序lst = [-90,-100,-1,90,78]# 从小到大进行排序（默认）lst.sort()# 从大到小进行排序lst.sort(reverse=True)print(lst)# 对字符串进行排序(按照ascii编码)lst = ["kobi","james","jordon","yaoming","yi"]lst.sort()print(lst) # ["james","jordon", "kobi","yaoming","yi"]# 是否可以对中文排序(了解 无规律可循)lst = ["王文","蔡徐坤"]lst.sort()print(lst)# 4. reverse 列表反转操作lst = [1,2,"a","蔡徐坤","易烊千玺"]lst.reverse()print(lst)

列表的深浅拷贝

copy模块中有 浅拷贝 和 深拷贝 两种方法

浅拷贝: 浅拷贝只拷贝外层列表 内层列表跟随原列表进行改变

浅拷贝copy.copy(listvar)或者listvar.copy()深拷贝: 拷贝整个列表 内外列表都不跟随原列表进行改变

深拷贝copy.deepcopy(listvar)

注意: copy模块的copy方法 和 python内置的函数copy一样 都是浅拷贝

# 1.浅拷贝import copy"""模块.方法() 同名模块下的同名方法"""# 方法一 (推荐)"""lst1 = [1,2,3]lst2 = copy.copy(lst1)lst1.append(10)print(lst2)print(lst1)"""# 方法二"""lst1 = [1,2,3]lst2 = lst1.copy()lst1.append(11)print(lst1)print(lst2)"""# 2.深拷贝"""把所有层级的容器元素都单独拷贝一份,放到独立的空间中""""""# 现象lst1 = [1,2,3,[4,5,6]]lst2 = copy.copy(lst1)lst1[-1].append(77) # lst2 中最后一个元素也含有77lst1.append(8888)print(lst2)print(lst1)"""import copylst1 = [1,2,3,[4,5,6]]lst2 = copy.deepcopy(lst1)lst1[-1].append(999)print(lst2)print(lst1)# 其他容器的深拷贝lst1 = (1,2,3,{"a":1,"b":[10,20]})lst2 = copy.deepcopy(lst1)lst1[-1]["b"].append(30)print(lst1)print(lst2)"""总结:浅拷贝:只拷贝一级容器中的所有元素独立出一个单独的空间.深拷贝:把所有层级的容器中所有元素都单独拷贝一份,形成独立的空间"""

元组的内置方法

tuple 只有countindex两个方法，使用方法同上述列表的相同方法。

字典的相关方法

1. 增

(1) 常用-普通方法

dic["top"] = "369"dic["middle"] = "左手"dic["bottom"] = "杰克爱"print(dic)

(2)fromkeys使用一组键和默认值创建字典

tup = ("a","b","c")# fromkeys(盛放键的容器,默认值)dic = {}.fromkeys(tup,None)print(dic) # {'a': None, 'b': None, 'c': None}

(3) 注意点 (字典中的三个键默认指向的是同一个列表)

dic= {}.fromkeys(tup,[])print(dic)dic["a"].append(1)print(dic) # {'a': [1], 'b': [1], 'c': [1]}# 改造dic = {}dic["top"] = []dic["middle"] = []dic["bottom"] = []dic["top"].append("the boy")print(dic)

2. 删

(1)pop()通过键去删除键值对 (若没有该键可设置默认值,预防报错)

dic = {'top': '369', 'middle': '左手', 'bottom': '杰克爱'}res = dic.pop("middle")print(res) # 左手print(dic) # {'top': '369', 'bottom': '杰克爱'}# 可以给pop设置第二个参数值,以防止键不存在时报错# 如果没加第二个参数，当key不存在时会报错res = dic.pop("middle1234","该键不存在")print(res) # 该键不存在

(2)popitem()删除最后一个键值对

dic = {'top': '369', 'middle': '左手', 'bottom': '杰克爱'}res = dic.popitem()print(res) # {'bottom': '杰克爱'}print(dic) # {'top': '369', 'middle': '左手'}

(3)clear()清空字典

dic.clear()print(dic) # {}

3. 改

update()批量更新(有该键就更新,没该键就添加)

# 推荐使用# 没该键就添加dic_new = {"jungle":"karsa","support":"宝蓝"}dic = {'top': '369', 'middle': '左手', 'bottom': '杰克爱'}dic.update(dic_new)print(dic)# 有该键就更新dic_new = {"top":"the bug","support":"xboyww","xiaozhang":"王思聪"}dic.update(dic_new)print(dic)# (了解)dic.update(ww="王文",zl="张磊")print(dic)

4. 查

get()通过键获取值(若没有该键可设置默认值,预防报错)

dic = {"top":"the bug","support":"xboyww","xiaozhang":"王思聪"}# res = dic["top123"] # 当键不存在时会报错# get 在获取字典键时,如果不存在,不会发生任何报错,返回的是Noneres = dic.get("top123")# 可以在获取不到该键时,给与默认值提示.res = dic.get("top123","抱歉,该键不存在")print(res)

5. 遍历相关

keys()将字典的键组成新的可迭代对象

dic = {"top":"the bug","support":"xboyww","xiaozhang":"王思聪"}res = dic.keys()print(res , type(res)) # <class 'dict_keys'> for i in res:print(i)

values()将字典中的值组成新的可迭代对象 ***

res = dic.values()print(res , type(res)) # <class 'dict_values'>

items()将字典的键值对凑成一个个元组,组成新的可迭代对象 ***

res = dic.items()print(res , type(res))for k,v in res:print(k,v)

集合相关操作

交差并补

(1)intersection()交集

set1 = {"易烊千玺","王一博","刘某PDD","王文"}set2 = {"倪萍","赵忠祥","金龟子大风车","小龙人","王文"}res = set1.intersection(set2)print(res) # {"王文"}# 简写 &res = set1 & set2print(res) # {"王文"}

(2)difference()差集

res = set1.difference(set2)print(res)# 简写 -res = set1 - set2print(res) # {"易烊千玺","王一博","刘某PDD"}

(3)union()并集

res = set1.union(set2)print(res)# 简写 |res = set1 | set2print(res) # {"易烊千玺","王一博","刘某PDD","倪萍","赵忠祥","金龟子大风车","小龙人","王文"}

(4)symmetric_difference()对称差集 (补集情况涵盖在其中)

res = set1.symmetric_difference(set2)print(res)# 简写 ^res = set1 ^ set2print(res) # # {"易烊千玺","王一博","刘某PDD","倪萍","赵忠祥","金龟子大风车","小龙人"}

(5)issubset()判断是否是子集

set1 = {"刘德华","郭富城","张学友","王文"}set2 = {"王文"}res = set2.issubset(set1)print(res)# 简写 res = set2 < set1print(res) # True

(6)issuperset()判断是否是父集

set1 = {"刘德华","郭富城","张学友","王文"}set2 = {"王文"}res = set1.issuperset(set2)print(res)# 简写res = set1 > set2print(res) # True

(7)isdisjoint()检测两集合是否不相交 不相交 True 相交False

set1 = {"刘德华","郭富城","张学友","王文"}set2 = {"王文"}res = set1.isdisjoint(set2)print(res) # False 即相交

集合的相关方法

增，删

1. 增

add()向集合中添加数据

# 一次加一个set1 = {"王文"}set1.add("王伟")print(set1)

update()迭代着增加

# 一次加一堆set1 = {"王文"}lst = ["a","b","c"]lst = "ppp" # 迭代这添加,无序,会自动去重set1.update(lst)print(set1)

2. 删

clear()清空集合

setvar = {'刘某PDD', '小龙人','倪萍', '赵忠祥'}setvar.clear()print(setvar)

pop()随机删除集合中的一个数据

res = setvar.pop()print(res) # 小龙人 print(setvar) # 直接改变原集合 #{'刘某PDD', '倪萍', '赵忠祥'}

discard()删除集合中指定的值(不存在的不删除 推荐使用) ***

setvar.discard("刘某PDD111111") # 元素不存在，也不报错，存在则直接删除，修改原集合# setvar.discard("刘某PDD") # success 返回值为Noneprint(setvar)

remove()删除集合中指定的值(不存在则报错) (了解)

setvar.remove("刘某PDD111") # 元素不存在会报错setvar.remove("刘某PDD")print(setvar)

3.frozenset冰冻集合 (额外了解)

"""frozenset 单纯的只能做交差并补操作,不能做添加或者删除的操作"""lst = ["王文","宋健","何旭彤"]fz1 = frozenset(lst)print(fz1, type(fz1)) # frozenset(["王文","宋健","何旭彤"]) <class 'frozenset'># 不能再冰冻集合中添加或者删除元素# fz1.add(1) # 报错# fz1.update("abc") # 报错# fz1.discard("王文") # 报错# 冰冻集合只能做交差并补lst2 = ["王文","王同培","刘一缝"]fz2 = frozenset(lst2)print(fz2, type(fz2))# 交集res = fz1 & fz2print(res) # frozenset(["王文"]) # 遍历冰冻集合for i in fz2:print(i)