Arnaud Delobelle schrieb:
If you want to simply 'set' the generator (by which I take you mean
'change its state') without without iterating it one step, then what you
need is a class with an __iter__() method. Then you can change the
state of the object between calls to next(). E.g.
class MyGenerator(object):
... def __init__(self, v): self.v = v
... def __iter__(self):
... for x in range(10):
... yield self.v
...
g = MyGenerator(5)
for i in g:
... g.v = input("val:")
... print i
That's a good idea, thanks! Meanwhile I have succeeded in writing a
decorator which allows an argument for next():
def myway( g ):
class mygen( object ):
def __init__( self, n ):
self.g = g( n )
def __iter__( self ):
return self
def next( self, s = None ):
return self.g.next() if s is None else self.g.send( s )
def send( self, s ):
return self.g.send( s )
return mygen
@myway
def gen( n ):
i = 0
while i <= n:
s = yield i
if s is not None:
i = s
else:
i += 1
Of course, this is just an exercise -- it doesn't look as if it's worth
using @mayway in any "real" code just to be able to write g.next(42)
instead of g.send(42). Still, I would like to know why it was decided to
introduce a send() method instead of allowing an argument for next().
Thanks and greetings,
Thomas
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