在__iter__方法中需要返回self 下面我们仿照内置iter的形式来创建自己的迭代器 class MyIter(): def __init__(self, lst): self.lst = lst self.idx = 0 self.len = len(lst) def __next__(self): if self.idx >= self.len: raise StopIteration self.idx += 1 return self.lst[self.idx-1...
for item in Iterable 循环的本质就是先通过iter()函数获取可迭代对象Iterable的迭代器,然后对获取到的迭代器不断调用next()方法来获取下一个值并将其赋值给item,当遇到StopIteration的异常后循环结束 # 随便定义一个list listArray=[1,2,3] # 使用iter()函数 iterName=iter(listArray) print(iterName) 结果如...
classFib:def__init__(self):self.prev=0self.cur=1def__iter__(self):returnselfdef__next__(self):val=self.curself.cur+=self.prevself.prev=valreturnval>>>fib=Fib()>>>next(fib)1>>>next(fib)1>>>next(fib)2 iterable iterable(可迭代对象)是一个更加底层的概念,只要具有__iter__()方法...
classMyIterator:def__init__(self, iterable): self.iterable = iterable self.index = def__iter__(self):return selfdef__next__(self):if self.index < len(self.iterable): result = self.iterable[self.index] self.index +=1return resultelse:raise StopIteration# 创建一个可迭代对象...
clf=LogisticRegression()#fit函数返回的结果就是self, 允许链式调用t =clf.fit(X,y)print(t) 输出: LogisticRegression(C=1.0, class_weight=None, dual=False, fit_intercept=True,intercept_scaling=1, max_iter=100, multi_class='ovr', n_jobs=1,penalty='l2', random_state=None, solver='liblinear...
classMyIterator:def__init__(self, iterable): self.iterable = iterable self.index =0def__iter__(self):returnselfdef__next__(self):ifself.index <len(self.iterable): result = self.iterable[self.index] self.index +=1returnresultelse:raiseStopIteration# 创建一个可迭代对象my_list = [1,2,...
0 self.data = [1, 2, 3] def __iter__(self): return self def __next__(self): if self.index >= len(self.data): raise StopIteration result = self.data[self.index] self.index += 1 return resultmy_iterator = MyIterator()for i in my_iterator: print...
self.limit = limit self.n = 0 def __iter__(self): return self def __next__(self): self.n += 1 if self.n <= self.limit: return self.n raise StopIteration result = Positive(5) for n in result: print(n) 1 2 3 4
生成器是一种特殊的迭代器,但它不是通过定义__iter__()和__next__()方法来实现 ,而是使用def关键字定义一个包含yield语句的函数。当调用这样的函数时,不会立即执行函数体 ,而是返回一个生成器对象。每次通过next()函数(或for循环)请求下一个值时 ,函数从上次暂停的地方继续执行 ,直到遇到下一个yield表达式,...
/usr/bin/python# -*- coding: UTF-8 -*-classFab(object):def__init__(self,max):self.max=maxself.n,self.a,self.b=0,0,1def__iter__(self):returnselfdefnext(self):ifself.n<self.max:r=self.bself.a,self.b=self.b,self.a+self.bself.n=self.n+1returnrraiseStopIteration()for...