[Python-Dev] Tricky way of of creating a generator via a comprehension expression

David Mertz mertz at gnosis.cx
Sat Nov 25 19:20:34 EST 2017

On Sat, Nov 25, 2017 at 3:37 PM, Guido van Rossum <guido at python.org> wrote:

> Maybe you didn't realize async/await don't need an event loop? Driving an
> async/await-based coroutine is just as simple as driving a yield-from-based
> one (`await` does exactly the same thing as `yield from`).

I realize I *can*, but it seems far from straightforward.  I guess this is
really a python-list question or something, but what is the async/await
spelling of something toy like:

In [1]: def fib():
   ...:     a, b = 1, 1
   ...:     while True:
   ...:         yield a
   ...:         a, b = b, a+b

In [2]: from itertools import takewhile

In [3]: list(takewhile(lambda x: x<200, fib()))
Out[3]: [1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144]

> Maybe the rest of the discussion should be about deprecation vs.
> SyntaxError in Python 3.7.

I vote SyntaxError, of course. :-)

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