2022-10-19 学习Python-Day19

wyh551202

这几天学习类与对象，晕乎乎的

###########################################P67 对象与类
class S(str):
    def __add__(self,other):
        print('qq',self,other)
        return len(self)+len(other)
s1=S('Fishc')
s2=S('ee')
s3=S('fff')
print(s1+s2)
class S1(str):
    def __add__(self, other):
        return NotImplemented
class S2(str):
    def __radd__(self, other):
        return len(self)+len(other)
s1=S1('Apple')
s2=S2('Banana')
print(s1+s2)
class S1(str):
    def __iadd__(self, other):
        return len(self)+len(other)
s1=S1('Apple')
s1+=s2
print(s1)
s2+=s2
print(s2)
###########################################P66 对象与类
print(bin(22))
print(~22)
print(9>>2)
print(0.1+0.2)
class C:
    def __index__(self):
        print('拦截')
        return 3
c=C()
# print(list(c))
s='FishC'
print(s[c])
##################
class C:
    def __getitem__(self, index):
        print(index)
c=C()
c[2]
c[2:8]
s='I love FishC'
print(s[2:6])
print(s[slice(2,6)])
print(s[7:])
print(s[slice(7,None)])
print(s[::4])
print(s[slice(None,None,4)])
class D:
    def __init__(self,data):
        self.data=data
    def __getitem__(self, index):
        return self.data[index]
    def __setitem__(self, index, value):
        self.data[index]=value
d=D([1,2,3,4,5])
print(d[1])
d[1]=1
d[2:4]=[2,3]
print(d[:])
class D:
    def __init__(self,data):
        self.data=data
    def __getitem__(self, index):
        return self.data[index]*2
d=D([1,2,3,4,5])
for i in d:
    print(i,end=' ')
class Double:
    def __init__(self,start,stop):
        self.value = start-1
        self.stop=stop
    def __iter__(self):
        return self
    def __next__(self):
        if self.value ==self.stop:
            raise StopIteration
        self.value +=1
        return self.value*2
d =Double(1,5)
for i in d:
    print(i,end=' ')