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Re: Using Pool map with a method of a class and a list

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On Tue, Aug 6, 2013 at 6:12 PM, Luca Cerone <luca.cerone@gmail.com> wrote:
> from multiprocessing import Pool
>
> class A(object):
>    def __init__(self,x):
>        self.value = x
>    def fun(self,x):
>        return self.value**x
>
>
> l = range(10)
>
> p = Pool(4)
>
> op = p.map(A.fun,l)

Do you ever instantiate any A() objects? You're attempting to call an
unbound method without passing it a 'self'.

You may find the results completely different in Python 2 vs Python 3,
and between bound and unbound methods. In Python 3, an unbound method
is simply a function. In both versions, a bound method carries its
first argument around, so it has to be something different. Play
around with it a bit.

ChrisA

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Thread

Using Pool map with a method of a class and a list Luca Cerone <luca.cerone@gmail.com> - 2013-08-06 10:12 -0700
  Re: Using Pool map with a method of a class and a list Chris Angelico <rosuav@gmail.com> - 2013-08-06 18:38 +0100
    Re: Using Pool map with a method of a class and a list Luca Cerone <luca.cerone@gmail.com> - 2013-08-06 12:42 -0700
      Re: Using Pool map with a method of a class and a list Joshua Landau <joshua@landau.ws> - 2013-08-07 07:48 +0100
        Re: Using Pool map with a method of a class and a list Luca Cerone <luca.cerone@gmail.com> - 2013-08-07 01:33 -0700
          Re: Using Pool map with a method of a class and a list Joshua Landau <joshua@landau.ws> - 2013-08-07 10:47 +0100
            Re: Using Pool map with a method of a class and a list Luca Cerone <luca.cerone@gmail.com> - 2013-08-07 03:10 -0700
              Re: Using Pool map with a method of a class and a list Joshua Landau <joshua@landau.ws> - 2013-08-07 12:53 +0100
                Re: Using Pool map with a method of a class and a list Luca Cerone <luca.cerone@gmail.com> - 2013-08-07 15:26 -0700
                Re: Using Pool map with a method of a class and a list Joshua Landau <joshua@landau.ws> - 2013-08-07 23:49 +0100
              Re: Using Pool map with a method of a class and a list Peter Otten <__peter__@web.de> - 2013-08-07 16:46 +0200
              Re: Using Pool map with a method of a class and a list Joshua Landau <joshua@landau.ws> - 2013-08-07 16:52 +0100
              Re: Using Pool map with a method of a class and a list Peter Otten <__peter__@web.de> - 2013-08-07 18:15 +0200
                Re: Using Pool map with a method of a class and a list Luca Cerone <luca.cerone@gmail.com> - 2013-08-07 16:31 -0700
  Re: Using Pool map with a method of a class and a list Luca Cerone <luca.cerone@gmail.com> - 2013-08-06 12:37 -0700

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