Generators (yield). Send() method.

Question

Can somebody please explain me how does send() method work in generators?
https://code.sololearn.com/c28YFxTnaak2/?ref=app

Answer 1

Send makes the next yield
Docu says send(None) is equal to yield

Answer 2

I commented in code. that is indeed very interesting

Answer 3

After reading the docs and thinking a while, I come to the following result:
a.send(100) does not send x but the yield expression
yield x.
Python must do so, otherwise it had problems handling send() for a generator gen(x,y):
while True:
yield(3x +4y)
What would you send in this case if send has exactly 1 argument.
As a model u can regard yield x as a variable that is created with first yield and can be manipulated with send()

Answer 4

But if so, why in my second example (gen1) where generator uses double “yield” statement, b.send(100) prints out 100?

Answer 5

So, send() does the same as next()?
P.S. If you run my code now, you will see a very interesting thing in the second example with double “yield”! It looks like these two “yields” work one after another: with first “next()” it prints out the first element of generator (so I guess the inner “yield x” does this), but with second “next()” it prints out “None” (as if outer “yield” is doing this). And if I write “send(value)” instead of the second “next()”, it prints out the “value” of “send”!