一、列表(list)
1.列表的格式
li = [11,22,"kobe",["lakers","ball",11],(11,22,),{"k1":11,"k2":"kuzma"},True,False]
2.列表可以嵌套任何格式,数字、字符串、列表、元组、字典、布尔值。
3.索引取值
li = [11,22,"kobe",["lakers","ball",11],(11,22,),{"k1":11,"k2":"kuzma"},True,False] print(li[1])
4切片取值
li = [11,22,"kobe",["lakers","ball",11],(11,22,),{"k1":11,"k2":"kuzma"},True,False] print(li[1:-1])
5.for循环
li = [11, 22, "kobe", ["lakers", "ball", 11], (11, 22,), {"k1": 11, "k2": "kuzma"}, True, False] for item in li: print(item)
6.利用索引修改和删除
修改
li = [11, 22, "kobe", ["lakers", "ball", 11], (11, 22,), {"k1": 11, "k2": "kuzma"}, True, False] li[2] = "randle" print(li)
删除
li = [11, 22, "kobe", ["lakers", "ball", 11], (11, 22,), {"k1": 11, "k2": "kuzma"}, True, False] del li[1] print(li)
7.利用切片修改和删除
修改
li = [11, 22, "kobe", ["lakers", "ball", 11], (11, 22,), {"k1": 11, "k2": "kuzma"}, True, False] li[0:2] = [33,44] print(li)
删除
li = [11, 22, "kobe", ["lakers", "ball", 11], (11, 22,), {"k1": 11, "k2": "kuzma"}, True, False] del li[0:4] print(li)
8.in 操作
li = [11, 22, "kobe", ["lakers", "ball", 11], (11, 22,), {"k1": 11, "k2": "kuzma"}, True, False] v ="ball" in li print(v)
9.查找
li = [11, 22, "kobe", ["lakers", "ball", 11], (11, 22,), {"k1": 11, "k2": "kuzma"}, True, False] v = li[3][2] print(v)
10.转换
字符串转列表
s = "hechouzi" li = list(s) print(li)
列表转字符串
a.列表中有数字,要用for循环
li = [11, 22, "kobe", ["lakers", "ball", 11], (11, 22,), {"k1": 11, "k2": "kuzma"}, True, False] s = "" for item in li: s = s + str(item) print(type(s),s)
b.列表中只有字符串
li = ["123","hahah"] v = "".join(li) print(v)
11.方法
(1)append 原来值最后追加
li = [11, False, "kobe", ["lakers"], (11, 22,), {"k1": 11, "k2": "kuzma"}] li.append(22) print(li)
(2)clear 清空列表
li = [11, False, "kobe", ["lakers"], (11, 22,), {"k1": 11, "k2": "kuzma"}] li.clear() print(li)
(3)copy (浅拷贝)
li = [11, False, "kobe", ["lakers"], (11, 22,), {"k1": 11, "k2": "kuzma"}] v = li.copy() print(v)
(4)count 计算元素出现的次数
li = [11, False,0, "kobe", ["lakers"], (11, 22,), {"k1": 11, "k2": "kuzma"}] v = li.count(False) print(v)
(5)extend 扩展原列表,参数:可迭代对象
li = [11, False,0, "kobe", ["lakers"], (11, 22,), {"k1": 11, "k2": "kuzma"}] li.extend([(11,22),"33"]) print(li)
(6)index 根据值获取当前值的索引位置(左边优先)
li = [11, False,0, "kobe", ["lakers"], (11, 22,), {"k1": 11, "k2": "kuzma"}] v = li.index(False) print(v)
(7)insert 在指定索引位置插入元素
li = [11, False,0, "kobe", ["lakers"], (11, 22,), {"k1": 11, "k2": "kuzma"}] li.insert(2,"randle") print(li)
(8)pop(1:指定索引;2:默认删除最后一个) 删除某个值,并获取删除的值
li = [11, False,0, "kobe", ["lakers"], (11, 22,), {"k1": 11, "k2": "kuzma"}] v = li.pop() print(li,v)
(9)remove 删除列表中指定的值,左边优先
li = [11,22,33,33,44] li.remove(33) print(li)
(10)reverse 将列表进行翻转
li = [11,22,33,33,44] li.reverse() print(li)
(11)sort 排序
li = [11,22,33,33,44] li.sort(reverse = True) print(li)
二、元组(tuple)
1.元组的写法,一般在最后加,
tu = (11,"hehcouzi",)
2.元组的一级元素不可被修改,不能增加或删除
3.索引取值
tu = (11,"kobe",[22],{"key1":"ball"},) v = tu [1] print(v)
4.切片取值
tu = (11,"kobe",[22],{"key1":"ball"},) v = tu [1:-1] print(v)
5.for 循环
tu = (11, "kobe", [22], {"key1": "ball"},) for item in tu: print(item)
6.转换
s = "hehcouzi" v1 = tuple(s) v2 = list(v1) print(v1,v2)
三、字典(dict)
1.字典的基本结构
info = {“k1”:"v1","k2":"v2"}.key:value
2.字典的value可以是任何值
3.字典和列表不可做key值
4.字典是无序的
5.可以通过索引取值,不能切片
info = {"k1":11,"k2":"hechouzi","k3":("lakers"),1:22,True:11,} v = info["k1"] print(v)
6.del删除
info = {"k1":11,"k2":"hechouzi","k3":("lakers"),1:22,True:11,} del info["k1"] print(info)
7. for 循环,默认输出key值
a.info.items 输出key和value
info = {"k1":11,"k2":"hechouzi","k3":("lakers"),1:22,True:11,} for item in info.items(): print(item)
b.info.values 输出value值
info = {"k1":11,"k2":"hechouzi","k3":("lakers"),1:22,True:11,} for item in info.values(): print(item)
8.方法
(1)fromkeys 根据序列,创建字典,并赋予统一的值
v = dict.fromkeys(["k1","k2","k3"],"hahah") print(v)
(2)get
a.寻找指定key值的value,找不到报错
info = {"k1":11,"k2":"hechouzi","k3":("lakers"),1:22,True:11,} v =info["k1"] print(v)
b.寻找指定key值的value,找不到返回指定值,默认为None
info = {"k1":11,"k2":"hechouzi","k3":("lakers"),1:22,True:11,} v =info.get("k111",11111) print(v)
3. pop 删除并获取值
a.删除k1,并返回11111
info = {"k1":11,"k2":"hechouzi","k3":("lakers"),1:22,True:11,} v =info.pop("k1",11111) print(info,v)
b.随机删除一个key和它对应的value
info = {"k1":11,"k2":"hechouzi","k3":("lakers"),1:22,True:11,} k,v =info.popitem() print(k,v,info)
4.setdefault 设置值,已存在不设置并获取当前的value,不存在则设置并获取value
info = {"k1":11,"k2":"hechouzi","k3":("lakers"),1:22,True:11,} v = info.setdefault("k1",123) print(info,v)
5. update 更新
两种方法
info = {"k1":11,"k2":"hechouzi","k3":("lakers"),1:22,True:11,} # info.update({"k1":123,"k2":"hahaha"}) info.update(k1 = "lakers",k3=111,Ture=111) print(info)