Python一些代码，代码,自定义with op

Python一些代码，代码,自定义with op

自定义with open打开文件

 # 是使用上下文管理协议自定义openclass Open(object):    def __init__(self,filepath,mode=‘r‘,encoding=‘utf8‘):        self.filepath=filepath        self.mode=mode        self.encoding=encoding    def __enter__(self):        self.f=open(self.filepath,mode=self.mode,encoding=self.encoding)        return self.f    def __exit__(self, exc_type, exc_val, exc_tb):        print(‘别瞎写‘)        self.f.close()        return True    def __getattr__(self, item):        return getattr(self.f,item)with Open(‘a.txt‘,‘w‘) as f:    f.write(‘aaa‘)    f.jdhlasufh  #  触发异常，照样能写

自定义range

# 自定义rangeclass MyRange(object):    def __init__(self,start=0,end=None):        self.start=start        self.end=end    def __iter__(self):        return self    def __next__(self):        if self.start==self.end:            raise StopIteration        n=self.start        self.start+=1        return nfor i in MyRange(2,7):    print(i)

自定义栈

#  自定义栈class MyStack(list):    def is_empty(self):        return len(self)==0    def peek(self):        return self[0-1]    def size(self):        return len(self)    def push(self,item):        return self.append(item)stackobj=MyStack((1,22,3,5))stackobj.push(998)print(stackobj)print(stackobj.peek())print(stackobj.size())print(stackobj.is_empty())

自定义链表

class Node(object):    #  单个节点对象    def __init__(self,length):        self.length=length        self.next=Nonedef createlink(lst):    #  创建链表    head=Node(0)    for num in lst:        p=Node(num)        p.next=head.next        head.next=p        head.length+=1    return head    #  创建的链表只要有个头节点就可以代表整个链表def createlinktail(lst):    #  创建尾插法链表    head=Node(0)    tail=head    for num in lst:        p=Node(num)        tail.next=p        tail=p        head.length+=1    return headdef travellink(head):    p=head.next    while p is not None:        print(p.length)        p=p.nextlst=[1,23,44,56,]head=createlink(lst)travellink(head)print(‘---------------‘)tail_head=createlinktail(lst)travellink(tail_head)

Python一些代码