Python `yield from`, or return a generator?

Question

I wrote this simple piece of code:

def mymap(func, *seq):
  return (func(*args) for args in zip(*seq))

Should I use the \'return\' statemen

Answer 1

The most important difference (I don't know if yield from generator is optimized) is that the context is different for return and yield from.

[ins] In [1]: def generator():
         ...:     yield 1
         ...:     raise Exception
         ...:

[ins] In [2]: def use_generator():
         ...:     return generator()
         ...:

[ins] In [3]: def yield_generator():
         ...:     yield from generator()
         ...:

[ins] In [4]: g = use_generator()

[ins] In [5]: next(g); next(g)
---------------------------------------------------------------------------
Exception                                 Traceback (most recent call last)
 in 
----> 1 next(g); next(g)

 in generator()
      1 def generator():
      2     yield 1
----> 3     raise Exception
      4

Exception:

[ins] In [6]: g = yield_generator()

[ins] In [7]: next(g); next(g)
---------------------------------------------------------------------------
Exception                                 Traceback (most recent call last)
 in 
----> 1 next(g); next(g)

 in yield_generator()
      1 def yield_generator():
----> 2     yield from generator()
      3

 in generator()
      1 def generator():
      2     yield 1
----> 3     raise Exception
      4

Exception: