字典.笔记

#字典是无序存储的

# a=10
# print(id(a))
# b=a
# print(id(b))
# b=15
# print(id(b))
# print(a,b)

# dic={1:‘alex‘,‘age‘:‘35‘,‘hobby‘:{‘girl_name‘:‘铁锤‘,‘age‘:‘45‘},‘is_handsome‘:True}
# print(dic[‘hobby‘])
#字典两大特点：无序，键唯一


#字典的创建：
#a=[1,2,3] #列表的第一种的创建方式

#a=list()
# print(a)

# dic={‘name‘:‘alex‘}  #一般都是这种

#dic1=() #字典的1种创建方式
# dic2=dict(((‘name‘,‘alex‘),))
# print(dic2)

# dic3=dict([[‘name‘,‘alex‘],])
# print(dic3)


# dic1={‘name‘:‘alex‘} #增加内容
# dic1[‘age‘]=18
# print(dic1)

# dic1={‘name‘:‘alex‘}  #修改
# dic1[‘name‘]=18
# print(dic1)

# dic1={‘name‘:‘alex‘}
# dic1[‘age‘]=18
# print(dic1)
# setdefault 方法
#键存在，不改动，返回字典中相应的键对应的值
# ret=dic1.setdefault(‘age‘,‘34‘)
# print(ret)

#键不存在，在字典中增加新的键值对，并返回相应的值
# ret2=dic1.setdefault(‘hobby‘,‘girl‘)
# print(dic1)
# print(ret2)

#查   通过键去查找
# dic3={‘name‘: ‘alex‘, ‘age‘: 18, ‘hobby‘: ‘girl‘}
#
# print(dic3[‘name‘])
#
# print(list(dic3.keys()))
# print(list(dic3.values()))
# print(list(dic3.items()))

#改
# li=[1,2,34,4]
# li[2]=5
# dic3={‘name‘: ‘alex‘, ‘age‘: 18, ‘hobby‘: ‘girl‘}
# dic3[‘age‘]=55
# print(dic3)


# dic4={‘name‘: ‘alex‘, ‘age‘: 18, ‘hobby‘: ‘girl‘}
# #dic5={‘1‘:‘111‘,‘2‘:‘222‘}
# dic5={‘name‘:‘111‘,‘2‘:‘222‘}
# dic4.update(dic5)
# print(dic4)
# print(dic5)


#删
#dic5={‘name‘: ‘alex‘, ‘age‘: 18, ‘class‘:1}
# del dic5[‘name‘]#删除字典中指定键值对
# print(dic5)

# dic5.clear()#清空字典
# print(dic5)

# ret=dic5.pop(‘age‘)#删除字典中指定键值对，并返回该键值对的值
# print(ret)
# print(dic5)

# a=dic5.popitem()#随机删除某组键值对，并以元组方式返回值
# print(a,dic5)

# del dic5     #删除整个字典
# print(dic5)


#其他操作以及涉及到的方法

# dic6=dict.fromkeys([‘host1‘,‘host2‘,‘host3‘],‘test‘)
# print(dic6)#{‘host1‘: ‘test‘, ‘host2‘: ‘test‘, ‘host3‘: ‘test‘}
#
# dic6[‘host2‘]=‘abc‘
# print(dic6)


# dic6=dict.fromkeys([‘host1‘,‘host2‘,‘host3‘],[‘test1‘,‘tets2‘])
# print(dic6) #{‘host1‘: [‘test1‘, ‘tets2‘], ‘host2‘: [‘test1‘, ‘tets2‘], ‘host3‘: [‘test1‘, ‘tets2‘]}
#
# dic6[‘host2‘][1]=‘test3‘
# print(dic6)#{‘host1‘: [‘test1‘, ‘test3‘], ‘host2‘: [‘test1‘, ‘test3‘], ‘host3‘: [‘test1‘, ‘test3‘]}



# av_catalog = {
#     ‘欧美‘:{
#         "www.youporn.com":["很多免费的，世界最大的","质量一般"],
#         "www.pornhub,com":["很多免费的，也很大","质量比youporn高点"],
#         "letmedothistoyou.com":["多是自拍，高质量图片很多","资源不多，更新慢"],
#         "x-art.com":["质量很高，真的很高","全部收费，屌丝请绕行"]
#     },
#     "日韩":{
#         "tokyo-hot":{"质量怎样不清楚，个人已经不喜欢日韩范","听说是收费的"}
#     },
#     "大陆":{
#         "1024":["全部免费，真好，好人一生平安","服务器在国外，慢"]
#     }
# }
# av_catalog["大陆"]["1024"][1] += ",可以用爬虫爬下来"
# print(av_catalog["大陆"]["1024"])
#[‘全部免费，真好，好人一生平安‘, ‘服务器在国外，慢,可以用爬虫爬下来‘]

# av_catalog[‘欧美‘]["www.youporn.com"][1]=‘高清无码‘
# print(av_catalog)


# dic={5:‘555‘,2:‘666‘,4:‘444‘}
# dic.has_keye(5) #2.7版本里面有这个
# print(5 in dic) #判断 5 是否在字典里面

# print(sorted(dic.items()))#[(2, ‘666‘), (4, ‘444‘), (5, ‘555‘)]


# dic5={‘name‘:‘alex‘,‘age‘:18}
#
# for i in dic5:
#     print(i,dic5[i])#用这个效率比较高
#
# for i in dic5.items():
#     print(i)
#
# for i,v in dic5.items():
#     print(i,v)#这个效率低


#String 操作

# a="let‘s go"
# print(a)

#1.*重复输出字符串
#print("hello"*2)

#2.[] ,[:] 通过索引获取字符串，这里和列表的切片操作是相同的，具体内容见列表
# print("helloworld"[2:])

#3.关键字 in
# print(‘123‘in‘12345‘)
#print(‘e2l‘in ‘hello‘)

#4. %  格式字符串
# print(‘alex is a good teacher‘)
# print(‘%s is a good teacher‘%‘alex‘)#容错率高

#5.+  join 字符串的拼接
# a=‘123‘
# b=‘abc‘
# d=‘11‘
# # c=a+b
# # print(c)#这个效率低
#
# c=‘****‘.join([a,b,d])#join 字符串拼接方法
# print(c)

字典.笔记

原文：https://www.cnblogs.com/xzdjs/p/9532220.html