dic = {'姓名':'A','age':23,'地址':'hn'}
print ( dic['age'])
字典存储内容是通过键值对存储的，取出是通过键取值
字典取值，使用中括号，通过键 取的值
dic = [
{'姓名':'A','age':23,'地址':'hen'},
{'姓名':'b','age':24,'地址':'hdn'},
{'姓名':'c','age':25,'地址':[1,2,3,4,]},
]
print(dic[2]['地址'][2])
for temp in dic :
print(temp)
增加 字典键 = [值] 如果键值不存在 就增加新的键值对
dic = {'name':'li','id':2}
dic['age']=20
print(dic)
改 字典键 = [值] 如果键值存在 就修改键值
dic = {'name':'li','id':2}
dic['id'] = 6
print(dic)
删 字典.pop(键) 根据键删除指定的值 并返回值
dic = {'name':'li','id':2}
sid=dic.pop('id')
print(dic)
print(sid)
删 del 字典[键] 根据键删除指定的值
dic ={'id':12,'name':'li','age':20}
del dic['age']
print(dic)
清空 字典.clear() 清空字典里的所有键值对
dic ={'id':12,'name':'li','age':20}
dic.clear()
print(dic)
查 值 = 字典[键] 根据键查询值
dic ={'id':12,'name':'li','age':20}
val = dic['id']
print(val)
print ('*'*30)
查 字典.get(键 [,默认值]) 用Get方法通过键取值，值存在，返回值，不存在返回None,或默认值可修改
dic ={'id':12,'name':'li','age':20}
age = dic.get('age')
score = dic.get('score','无成绩')
print(age)
print(score)
查 len(字典) 计算字典元素个数，即键值对总数
dic ={'id':12,'name':'li','age':20}
lenth = len(dic)
print (lenth)
字典.keys() 返回所有的键
dic ={'id':12,'name':'li','age':20}
keys = dic.keys()
for i in keys :
print('%s %s'%(i,dic[i]))
print(i)
print(keys)
字典.keys() 返回所有的值
dic ={'id':12,'name':'li','age':20}
vals = dic.values()
for i in vals :
print(i)
print(vals)
字典.items() 返回所有的键值对
dic ={'id':12,'name':'li','age':20}
items = dic.items()
for i in items :
print(i)
print(items)
dic ={'id':12,'name':'li','age':20}
items = dic.items()
for k,v in items :
print('%s %s'%(k,v))
in 是否存在 只能查看键是否存在
dic ={'id':12,'name':'li','age':20}
print('id' in dic)
字典.copy() 返回一个新的字典
dic ={'id':12,'name':'li','age':20}
dic1 = dic.copy()
print(dic1)
字典.fromkeys(seq[key,key1.],val) seq 序列 返回一个新的字典 val 为初始值
dic ={'id':12,'name':'li','age':20}
dic1=dic.fromkeys([1,2,3],'q')
print (dic1)
字典.setdefault(key,default = None) 如果键key不在字典中，则向字典中添加key并使用默认值，若存在字典中则返回字典中的值
dic ={'id':12,'name':'li','age':20}
val=dic.setdefault('id')
print (dic)
print(val)
print(dic.setdefault('score',110))
print(dic)
字典1.update(字典2) 把字典2中的键值对更新到字典1中，不影响字典1
dic ={'id':12,'name':'li','age':20}
dic1 = {'score':110}
dic.update(dic1)
print(dic)
print(dic1)
