字典是python中唯一的映射类型，采用键值对（key-value）的形式存储数据。
python对key进行哈希函数运算，根据计算的结果决定value的存储地址，所以
字典是无序存储的，且key必须是可哈希的。可哈希表示key必须是不可变类型，
如：数字、字符串、元组。
字典(dictionary)是除列表意外python之中最灵活的内置数据结构类型。
列表是有序的对象结合，字典是无序的对象集合。两者之间的区别在于：
————>字典当中的元素是通过键来存取的，而不是通过偏移存取。
#Hostname:陈先生
#_Author:"Jayce Chan"
#Date:2019/1/9
#创建字典
#法一
dic1 = {'name':'Jayce',"age":'23',"sex":"male",'hobby':{'name':"Angle",'age':'22'}}
print(dic1)
#字典是可变类型，也可作为值来存储，但不能作键
#法二
# def __init__(self, seq=None, **kwargs): # known special case of dict.__init__
# """
# dict() -> new empty dictionary
# dict(mapping) -> new dictionary initialized from a mapping object's
# (key, value) pairs
# dict(iterable) -> new dictionary initialized as if via:
# d = {}
# for k, v in iterable:
# d[k] = v
# dict(**kwargs) -> new dictionary initialized with the name=value pairs
# in the keyword argument list. For example: dict(one=1, two=2)
# # (copied from class doc)
# """
dic2 = dict( [ ("name","Jayce"), ] )
print(dic2)
#字典两大特点：无序，键唯一
#增
dic2["Age"] = '18'
print(dic2) #{'name': 'Jayce', 'Age': '18'}
# setdefault(self, *args, **kwargs): # real signature unknown
# """
# Insert key with a value of default if key is not in the dictionary.
#
# Return the value for key if key is in the dictionary, else default.
# """
#setdefault()：键不存在，在字典中中增加新的键值对，并返回相应的值
ret1 = dic2.setdefault('hobby','girl')
print(ret1)
print(dic2)
#setdefault()：键存在，不改动，返回字典中相应的键对应的值
ret2 = dic2.setdefault('Age','20')
print(ret2)
print(dic2)
#查 通过键去查找
dic3 = {'name': 'Jayce', 'Age': '18', 'hobby': 'girl'}
print(dic3['hobby'])
#查键
# keys(self): # real signature unknown; restored from __doc__
# """ D.keys() -> a set-like object providing a view on D's keys """
print(dic3.keys()) #dict_keys(['name', 'Age', 'hobby'])
print(type(dic3.keys()))
#转换成列表
print(list(dic3.keys())) #['name', 'Age', 'hobby']
#查值
# values(self): # real signature unknown; restored from __doc__
# """ D.values() -> an object providing a view on D's values """
print(list(dic3.values())) # ['Jayce', '18', 'girl']
# items(self): # real signature unknown; restored from __doc__
# """ D.items() -> a set-like object providing a view on D's items """
print(list(dic3.items()))
#改
print(dic3)
dic3["Age"] = '20' #可修改
print(dic3) #{'name': 'Jayce', 'Age': '20'}
# update(self, E=None, **F): # known special case of dict.update
# """
# D.update([E, ]**F) -> None. Update D from dict/iterable E and F.
# If E is present and has a .keys() method, then does: for k in E: D[k] = E[k]
# If E is present and lacks a .keys() method, then does: for k, v in E: D[k] = v
# In either case, this is followed by: for k in F: D[k] = F[k]
# """
dic4 = {"1":"123",'name':"冷垚"}
dic3.update(dic4)
print(dic3)
print(dic4)
#删
dic5 = {'name':"冷垚",'age':'23',"sex":'male','class':'网络1501','stuNumber':'1518064003'}
print(dic5)
#删除字典中指定键值对
del dic5['name']
print(dic5)
#删除字典中指定键值对，并返回该键值对的值
ret3 = dic5.pop("age")
print(ret3)
print(dic5)
#opitem(): 随机删除一个键值对 ，并以元组方式返回值
# popitem(self): # real signature unknown; restored from __doc__
# """
# D.popitem() -> (k, v), remove and return some (key, value) pair as a
# 2-tuple; but raise KeyError if D is empty.
# """
a = dic5.popitem()
print(a)
print(dic5)
# clear() 清空字典
# clear(self): # real signature unknown; restored from __doc__
# """ D.clear() -> None. Remove all items from D. """
dic5.clear()
print(dic5)
#删除整个字典
# del dic5
# print(dic5)
#####其他操作以及涉及到的方法#####
#dict.fromkeys() :创建字典
# fromkeys(*args, **kwargs): # real signature unknown
# """ Create a new dictionary with keys from iterable and values set to value. """
dic6 = dict.fromkeys(['A','B','C'],'ad')
print(dic6) #{'A': 'ad', 'B': 'ad', 'C': 'ad'}
dic6['B'] = "123"
print(dic6) #{'A': 'ad', 'B': '123', 'C': 'ad'}
dic7 = dict.fromkeys(['A','B','C'],['aa','bb'])
print(dic7) #{'A': ['aa', 'bb'], 'B': ['aa', 'bb'], 'C': ['aa', 'bb']}
dic7['B'][1]='cc'
print(dic7) #{'A': ['aa', 'cc'], 'B': ['aa', 'cc'], 'C': ['aa', 'cc']}
# 字典的嵌套
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yourporn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,屌比请绕过"]
},
"日韩":{
"tokyo-hot":["质量怎样不清楚,个人已经不喜欢日韩范了","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"])
#排序
# sorted(*args, **kwargs): # real signature unknown
# """
# Return a new list containing all items from the iterable in ascending order.
#
# A custom key function can be supplied to customize the sort order, and the
# reverse flag can be set to request the result in descending order.
# """
dic8 = {5:'555',2:'666',4:"444"}
print(sorted(dic8.values()))
print(sorted(dic8.items()))
#遍历
dic00 = {'name':"冷垚",'age':'23',"sex":'male','class':'网络1501','stuNumber':'1518064003'}
#推荐使用①
#①
for i in dic00:
print(i,dic00[i])
#②
for i in dic00.items():
print(i)
#③
for i,v in dic00.items():
print(i,v)