s="可口可乐"
s1=s.join("非常可乐")
print(s1)非可口可乐常可口可乐可可口可乐乐

join可以把列表变成字符串, 把字符串变成列表.split()

s="_".join(["姚明","科比","麦迪","詹姆斯"])
print(s)
姚明_科比_麦迪_詹姆斯　　　　　　　　s="abc".join(["1","2","3"])
print(s)
1abc2abc3                     

lst=["科比",'奥尼尔',"霍华德","乔丹"]
for i in lst:              lst.remove(i)
print(lst)
['奥尼尔', '乔丹']

# ⽤pop删除试试看:li = [11, 22, 33, 44]for el in li:    　　li.pop()    # pop也不行 print(li) 结果: [11, 22]

li = [11, 22, 33, 44]for i in range(0, len(li)):    del li[i]print(li)结果: 报错# i= 0, 1, 2  删除的时候li[0] 被删除之后. 后⾯面⼀一个就变成了了第0个. # 以此类推. 当i = 2的时候. list中只有⼀一个元素. 但是这个时候删除的是第2个 肯定报错啊               

for i in range(0, len(li)):    # 循环len(li)次, 然后从后往前删除
    li.pop()
print(li)

del_lst=[]
lst=["科比",'奥尼尔',"霍华德","乔丹"]
for i in lst:                                  del_lst.append(i)
for i in del_lst:                              lst.remove(i)
print(lst)
[]                                   

del_lst=[]
lst=["周星驰","周润发","周星星",'马化腾',"周树人","马周仁"]
for el in lst:                                     if el.startswith("周"):                         del_lst.append(el)
for el in del_lst:                                 lst.remove(el)
print(lst)
['马化腾', '马周仁']                                        

dic = {"a":"123", "b":"456"}
for k in dic:                 dic.setdefault("c", "123")
print(dic)结果:报错

a = dict.fromkeys(["jj", 'jay', 'taibai'], "sb")  # 静态方法
print(a)
{'jj': 'sb', 'jay': 'sb', 'taibai': 'sb'}

dic = dict.fromkeys(["jay", "JJ"], ["周杰伦", "麻花藤"])
print(dic)
{'jay': ['周杰伦', '麻花藤'], 'JJ': ['周杰伦', '麻花藤']}
dic.get("jay").append("胡⼤")
print(dic)
{'jay': ['周杰伦', '麻花藤', '胡⼤'], 'JJ': ['周杰伦', '麻花藤', '胡⼤']}                                              

dic={"黑旋风":"李逵","及时雨":"宋江","智多星":"吴用"}
for k in dic:                                             if "k" in k:                                          del dic[k]
print(dic)
{'黑旋风': '李逵', '及时雨': '宋江', '智多星': '吴用'}
在循环迭代的时候不允许进行删除操作                                                

del_dic=[]
dic={"黑旋风":"李逵","及时雨":"宋江","智多星":"吴用"}
for i in dic:                                                  del_dic.append(i)
for i in del_dic:                                              del dic[i]
print(dic)
{}                                                     

s={"科比","保罗","乔丹","詹姆斯","詹姆斯","True",'True'}
print(s)
{'詹姆斯', '保罗', '乔丹', 'True', '科比'}                                                      

lst=["德玛","剑姬","诺手","剑姬","德玛"]
s=set(lst)
print(s)
{'诺手', '剑姬', '德玛'}变回来

lst=list(s)print(lst)['德玛', '诺手', '剑姬']                                  

s={"张无忌","赵敏","周芷若"}
s.add("谢逊")
print(s)
{'赵敏', '周芷若', '谢逊', '张无忌'}
s.add("谢逊")
print(s)
{'赵敏', '周芷若', '谢逊', '张无忌'}               

迭代更新
s={"英雄联盟","吃鸡","王者荣耀"}
s.update("孙悟空")
print(s)
{'英雄联盟', '王者荣耀', '悟', '空', '吃鸡', '孙'}

s.update(["斗地主","魂斗罗"])print(s){'王者荣耀', '魂斗罗', '吃鸡', '斗地主', '英雄联盟'}           

s={"周杰伦","周星驰","周树人","周润发","陈一白"}
a=s.pop()
print(a)
结果:随便弹出一个                                             

s={"周杰伦","周星驰","周树人","周润发","陈一白"}
s.remove("陈一白")
print(s)
{'周树人', '周星驰', '周杰伦', '周润发'}                                             

s={"周杰伦","周星驰","周树人","周润发","陈一白"}
s.clear()
print(s)
set()清空set集合.需要注意的是set集合如果是空的. 打印出来是set() 因为要和 dict区分的.

s={"a","b","c","d"}
for el in s:       print(el)
a
b
d
c

s = frozenset(["赵本山", "小沈阳", "宋小宝", "岳云鹏"])
dic = {s:'A'}
print(dic)
{frozenset({'宋小宝', '小沈阳', '岳云鹏', '赵本山'}): 'A'}                                                 

s1 = {"刘能", "赵四", "⽪⻓⼭"}
s2 = {"刘科⻓", "冯乡⻓", "⽪⻓⼭"} 

# 交集 # 两个集合中的共有元素
print(s1 & s2)  # {'⽪⻓⼭'}
print(s1.intersection(s2))  # {'⽪⻓⼭'} 

# 并集print(s1 | s2)  # {'刘科长', '冯乡长', '赵四', '皮长山', '刘能'} print(s1.union(s2))     # {'刘科长', '冯乡长', '赵四', '皮长山', '刘能'}

# 差集 print(s1 - s2)  # {'赵四', '刘能'} 得到第一个中单独存在的 print(s1.difference(s2))     # {'赵四', '刘能'}

# 反交集print(s1 ^ s2)  # 两个集合中单独存在的数据 {'冯乡长', '刘能', '刘科长', '赵四'} print(s1.symmetric_difference(s2)) # {'冯乡长', '刘能', '刘科长', '赵四'}

s1 = {"刘能", "赵四"} s2 = {"刘能", "赵四", "皮长山"}# ⼦集print(s1 < s2)  # set1是set2的子集吗? True print(s1.issubset(s2))

# 超集print(s1 > s2) # set1是set2的超集吗? False print(s1.issuperset(s2)

lst1=["剑圣","剑魔","剑豪","剑姬"]
lst2=lst1
lst2.append("德玛")
print(lst2)
print(lst1)
['剑圣', '剑魔', '剑豪', '剑姬', '德玛']
['剑圣', '剑魔', '剑豪', '剑姬', '德玛']                               

dic1={"易大师":"剑圣","name":"剑姬"}
dic2=dic1
dic2["name"]  ="剑豪"
print(dic1)
print(dic2)
{'易大师': '剑圣', 'name': '剑豪'}
{'易大师': '剑圣', 'name': '剑豪'}                       

lst1=["詹姆斯","乔丹","科比","皮蓬"]
lst2=lst1.copy()              # lst2 和lst1 不是一个对象了  lst2=lst[:]切片会产生新的对象lst1.append("姚明")print(lst1) print(lst2) ['詹姆斯', '乔丹', '科比', '皮蓬', '姚明'] ['詹姆斯', '乔丹', '科比', '皮蓬'] 

lst1 = [ "七龙珠", "葫芦娃",  ["金城武", "王力宏", "渣渣辉"]]
lst2 = lst1.copy()     # 拷贝. 浅拷贝 拷贝第一层
lst1[2].append("大阳哥")
print(lst1, lst2)
['七龙珠', '葫芦娃', ['金城武', '王力宏', '渣渣辉', '大阳哥']]
['七龙珠', '葫芦娃', ['金城武', '王力宏', '渣渣辉', '大阳哥']]

import copy
lst1=["德玛","剑姬","火男","诺手",["劫","蒙多","剑魔"]]
lst2 = copy.deepcopy(lst1)
lst1[4] .append("剑圣")
print(lst1)
print(lst2)
['德玛', '剑姬', '火男', '诺手', ['劫', '蒙多', '剑魔', '剑圣']]
['德玛', '剑姬', '火男', '诺手', ['劫', '蒙多', '剑魔']]