revive a generator

Fri Oct 21 10:25:22 EDT 2011

On Fri, Oct 21, 2011 at 2:02 AM, Yingjie Lan <lanyjie at yahoo.com> wrote:
> Oops, my former reply has the code indentation messed up
> by the mail system. Here is a reformatted one:
>>> What if the generator involves a variable from another scope,
> and before re-generating, the variable changed its value.
> Also, the generator could be passed in as an argument,
> so that we don't know its exact expression.

In the former case, use a named generator function and call it twice
to create two generators. In the latter case, don't pass in the
generator as an argument. Pass in a callable that constructs the
iterator instead. Modifying your example:
vo = 34
def mygen():
 for x in range(3):
 yield vo * x
def myfun(g):
 global vo
 for i in g(): print(i)
 vo += 3
 for i in g(): print(i)
myfun(mygen)
Cheers,
Ian