老男孩python全栈就业班第14期第1部分-python基础-第7天-删除操作以及set集合

删除操作以及set集合

#删掉姓周的人
re_lst = []
lst = ['周杰伦', '周润发', '周星星', '马化腾', '周树人']
for l in lst:
    if "周" in l:
       re_lst.append(l)
for re_l in re_lst:
    lst.remove(re_l)

print(lst)


#fromkeys
dic = {"a":123}
s = dic.fromkeys("王键林", "思聪") #返回给你一个新的字典

#结果 {'王':'思聪','键':'思聪','林':'思聪'}
print(s)

#集合
#空集合
s = set()

#空字典
dic = dict()

#空字符串
s = str()

#空数值
i = int()

#空列表
lst = list()

s = {"a"}
print(type(s))

s = {"王者荣耀", "英雄联盟","王者荣耀",123,True, True}
print(s)

s = {123, {1,2,3}}
print(s) #报错

#去重复
lst = ["张强", "李强", ''王磊","刘伟","张伟","张伟", "刘洋","刘禅"]
s = set(lst)
print(s)

#变回来
lst = list(s)
print(lst)

#冻结了的set集合，可哈希的，不可变
s = frosenset([1,3,6,6,9,8]) #可以去重复，也是set集合
print(s)

ss = {"a", s}
print(ss)