Stupid ways to spell simple code

[88888 Dihedral]

Steven D'Aprano於 2013年7月2日星期二UTC+8上午6時09分18秒寫道：
> On Mon, 01 Jul 2013 20:36:29 +0100, Marcin Szamotulski wrote:
> 
> 
> 
> > Here is another example which I came across when playing with
> 
> > generators, the first function is actually quite useful, the second
> 
> > generator is the whole fun:
> 
> > 
> 
> > from functools import wraps
> 
> > def init(func):
> 
> >     """decorator which initialises the generator """
> 
> >     @wraps(func)
> 
> >     def inner(*args, **kwargs):
> 
> >         g = func(*args, **kwargs)
> 
> >         g.send(None)
> 
> >         return g
> 
> >     return inner
> 
> > 
> 
> > @init
> 
> > def gen(func):
> 
> >      x = (yield)
> 
> >      while True:
> 
> >          x = (yield func(x))
> 
> > 
> 
> > 
> 
> > now if you have function f
> 
> > def f(arg):
> 
> >     return arg**2
> 
> > 
> 
> > then calling f(5) is the same as
> 
> > 
> 
> > g = gen(f)
> 
> > g.send(5)
> 
> 
> 
> 
> 
> 
> 
> I think you must be missing an important part of the trick, because 
> 
> calling f(5) returns 25. It's not:
> 
> 
> 
> @gen
> 
> def f(arg):
> 
>     return arg**2
> 
> 
> 
> 
> 
> because that raises TypeError.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> -- 
> 
> Steven

Lets be serious about generators and iterators.

A generator can be used only once in a program
is different from a a generator method of a class that 
can produce several instances with generators of the same kind
but operated in each instance of the class.