Python学习笔记之迭代器

# 迭代器
# 能被next()调用，并不断的返回下一个值，叫迭代器
# 判断容器类型的迭代性
listvar = [1,3,3,5,6,7,8]
from collections.abc import Iterable,Iterator # Iterable 迭代性  |  Iterator 迭代器
for i in listvar:
    print(i)

res = isinstance(listvar, Iterable)
print(res)
res = isinstance(listvar, Iterator)
print(res)

# 判断range对象的迭代性
for i in range(6):
    print(i)
res = isinstance(range(6), Iterable)
res1 = isinstance(range(6), Iterator)
print(res, res1) # True 表示有迭代性  |  False 表示不是迭代器

# 把容器类型数据变为迭代器
listvar = [1,2,3]
listvarIterator = iter(listvar)
res = isinstance(listvarIterator, Iterator)
print(res) # True 表示是迭代器

# 使用next() 对迭代器进行调用
res = next(listvarIterator)
print(res) # 1
res = next(listvarIterator)
print(res) # 2
res = next(listvarIterator)
print(res) # 3

print('<-<-<-<-<-<-<-<-<<<-华丽分割线->>>->->->->->->->->')
for i in listvarIterator:
    print(i)

# range 迭代器
rangevar = iter(range(5))
print(isinstance(rangevar, Iterable)) # True
print(isinstance(rangevar, Iterator)) # True
print(next(rangevar)) # 0