#========================文件类字典增删改
a={ ‘001’:{‘name’:‘张三’,‘age’:18,‘address’:‘北京’},
‘002’:{‘name’:‘张二’,‘age’:28,‘address’:‘上海’},
‘003’:{‘name’:‘张大’,‘age’:38,‘address’:‘北京’},
‘004’:{‘name’:‘张四’,‘age’:28,‘address’:‘上海’},
‘005’:{‘name’:‘张六’,‘age’:38,‘address’:‘北京’}
}
class StudentAdmin():
@staticmethod
def write():
f=open(‘j.txt’,‘w’,encoding=‘utf-8’)
f.write(str(a))
f.close()
@staticmethod
def read():
f=open(‘j.txt’,‘r’,encoding=‘utf-8’)
c=f.read()
f.close()
return eval©
a=StudentAdmin.read()
while True:
bh=int(input(‘请输入编号：’))
if bh==1:
xh=int(input(‘请输入一个学号：’))
if xh in a.keys():
print(‘学号重复’)
continue
else:
zd={}
zd[‘name’]=input(‘请输入姓名：’)
zd[‘age’]=int(input(‘请输入年龄：’))
zd[‘address’]=input(‘请输入地址：’)
a[xh]=zd
elif bh==2:
xh=input(‘请输入学号：’)
if xh not in a.keys():
print(‘查无此人’)
continue
else:
print(‘要删除的是：’,a[xh])
del a[xh]
print(a)
elif bh==3:
xh=input(‘请输入一个学号：’)
if xh not in a.keys():
print(‘查无此人’)
continue
else:
a[xh][‘name’]=input(‘请输入姓名：’)
a[xh][‘age’]=int(input(‘请输入年龄：’))
a[xh][‘address’]=input(‘请输入地址：’)
print(a)
print(‘修改’)
elif bh==4:
xh = input(‘请输入一个学号：’)
if xh not in a.keys():
print(‘查无此人’)
continue
else:
print(a[xh])
print(‘查’)
elif bh==0:
StudentAdmin.write()
break
#===================================================
class A():
count=0
def init(self,name):
self.name=name
A.count+=1
def del(self):
A.count-=1
print(‘删除’,self.name,‘还剩%d个对象’%A.count)
a=A(‘张三’)
b=A(‘李四’)
del a
del b
class A():
count=0
def init(self,name):
self.name=name
A.count+=1
def del(self):
A.count-=1
print(‘删除’,self.name,‘还剩%d个对象’%A.count)
a=A(‘张三’)
b=A(‘李四’)
del a
del b
class Num():
def init(self,n):
self.n=n
def add(self, other):
return self.n+other.n
a=Num(5)
b=Num(6)
c=a+b
print©
#=============================
class Num():
def init(self,n):
self.n=n
def call(self, *args, **kwargs):
result=self.n
for a in args:
result*=a
for k,v in kwargs.items():
result+=v
return result
a=Num(5)
c=a(1,2,3,age=4,sg=5)
print©
#=======================
class Car():
obj=’’
xx=’’
def new(cls, *args, **kwargs):
print(‘我在这’)
return object.new(Car)
def init(self,name,cid):
print(‘你好’)
self.name=name
self.cid=cid
bmw=Car(‘宝马’,‘京A66666’)
print(hasattr(Car,‘obj’))
print(hasattr(Car,‘xx’))
#===============================
class Car():
def new(cls, *args, **kwargs):
if not hasattr(Car,‘inst’):#如果Car里面没有inst属性
Car.inst=object.new(Car)#就建立一个Car对象，给inst属性
return Car.inst#返回一个属性inst
def init(self,name,cid):
print(‘你好’)
self.name=name
self.cid=cid
a=Car(‘宝马’,‘京A66666’)
b=Car(‘奔驰’,‘京B66666’)
print(a.name,a.cid)
print(b.name,b.cid)