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TypeError: unbound method

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ronn.ross at gmail

Jul 16, 2009, 5:57 PM

Post #1 of 3 (250 views)
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TypeError: unbound method

Hello all,

Created a python file that has a class and three methods. When I jump into
interactive mode I import like so:

from <file> import <class>

Now when I try to use a method from the class:

var1 = class.method()

It give me this error:
TypeError: unbound method <methodname> must be called with <classname>
instance as first argument (got int instance instead)

I'm not sure what is going on event after consulting with google

clp2 at rebertia

Jul 16, 2009, 6:08 PM

Post #2 of 3 (233 views)
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Re: TypeError: unbound method [In reply to]

On Thu, Jul 16, 2009 at 5:57 PM, Ronn Ross<ronn.ross [at] gmail> wrote:
> Hello all,
>
> Created a python file that has a class and three methods. When I jump into
> interactive mode I import like so:
>
> from <file> import <class>
>
> Now when I try to use a method from the class:
>
> var1 = class.method()
>
> It give me this error:
> TypeError: unbound method <methodname> must be called with <classname>
> instance as first argument (got int instance instead)
>
> I'm not sure what is going on event after consulting with google

You're trying to call an instance method on the class itself, which
doesn't make sense.
You need to first create an instance of the class to invoke the method on.
i.e.:

instance = TheClass(constuctor_arguments_here)
var1 = instance.method()

Cheers,
Chris
--
http://blog.rebertia.com
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steve at REMOVE-THIS-cybersource

Jul 17, 2009, 12:56 AM

Post #3 of 3 (237 views)
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Re: TypeError: unbound method [In reply to]

On Thu, 16 Jul 2009 18:08:45 -0700, Chris Rebert wrote:

> You're trying to call an instance method on the class itself, which
> doesn't make sense.

Oh I don't know, people do it all the time -- just not the way the OP
did :)

> You need to first create an instance of the class to invoke the method
> on. i.e.:
>
> instance = TheClass(constuctor_arguments_here)
> var1 = instance.method()

Or explicitly pass an instance to the method when calling from the class:

TheClass.method(TheClass(constuctor_arguments_here))

Which strangely enough, is useful at times.

class K(parent):
def method(self, args):
x = parent.method(self, args)
return x + 1

--
Steven
--
http://mail.python.org/mailman/listinfo/python-list

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