On Thu, Dec 24, 2015 at 3:54 PM, Danny Yoo <d...@hashcollision.org> wrote:
I tried to follow your example:
>
> For example, here's a generator that knows how to produce an infinite
> stream of numbers:
>
> ##############
> def nums():
> n = 0
> while True:
> yield n
> n += 1
> ##############
>
> What distinguishes a generator from a regular function? The use of
> "yield". A "yield" is like a return, but rather than completely
> escape out of the function with the return value, this generator will
> remember what it was doing at that time. Why? Because it can
> *resume* itself when we try to get another value out of the generator.
>
> Let's try it out:
>
> #####################
>
>>>> numStream = nums()
>>>> numStream.next()
> 0
But I got an exception:
Python 3.4.4 (v3.4.4:737efcadf5a6, Dec 20 2015, 20:20:57) [MSC v.1600
64 bit (AMD64)] on win32
Type "copyright", "credits" or "license()" for more information.
>>> def nums():
n = 0
while True:
yield n
n += 1
>>> numStream = nums()
>>> numStream.next()
Traceback (most recent call last):
File "<pyshell#3>", line 1, in <module>
numStream.next()
AttributeError: 'generator' object has no attribute 'next'
If I instead do this:
>>> next(numStream)
0
>>> next(numStream)
1
>>> next(numStream)
2
Things work as you described. Is your example from Python 2? If yes,
is this something that changed between Python 2 and 3? I have not
made it to generators yet, but you have now whetted my appetite!
TIA!
boB
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