23.11.17 14:30, Antoine Pitrou пише:
On Thu, 23 Nov 2017 14:17:32 +0200
Serhiy Storchaka <storch...@gmail.com> wrote:
I used the "yield" statement, but I never used the "yield" expressions.
And I can't found examples. Could you please present a real-world use
case for the "yield" (not "yield from") expression?
Of course I can. "yield" expressions are important for writing
Python 2-compatible asynchronous code while avoiding callback hell:
See e.g. http://www.tornadoweb.org/en/stable/gen.html
or https://jdb.github.io/concurrent/smartpython.html
There are tons of real-world code written using this scheme (as opposed
to almost no real-world code, even Python 2-only, using "yield" in
comprehensions or generation expressions).
Thank you. The tornado examples contain the following equivalence code
for `results = yield multi(list_of_futures)`:
results = []
for future in list_of_futures:
results.append(yield future)
Couldn't this by written as `results = [(yield future) for future in
list_of_futures]`?
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