For implementing iterator, it is needed to implement _iter_ and _next_ method
_iter_ return the class instance
_next_ for handling ther next iter and when to stop
class AsyncIterator():
# constructor, define some state
def __init__(self):
self.counter = 0
# create an instance of the iterator
def __aiter__(self):
return self
# return the next awaitable
async def __anext__(self):
# check for no further items
if self.counter >= 10:
raise StopAsyncIteration
# increment the counter
self.counter += 1
# return the counter value
return self.counter
async def test():
it = AsyncIterator()
async for result in it:
print(result)
await test()
/**
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**/
Generator
Similar with Generator, but using yield
class AsyncIterator():
# constructor, define some state
def __init__(self):
self.counter = 0
# create an instance of the iterator
def __aiter__(self):
return self
# return the next awaitable
async def __anext__(self):
# check for no further items
if self.counter >= 10:
raise StopAsyncIteration
# increment the counter
self.counter += 1
# return the counter value
return self.counter
async def test():
it = AsyncIterator()
async for result in it:
print(result)
await test()
/**
start
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end
**/
