new.instancemethod convert to python 3.3 in overloading script

Question

I want to start out by saying I'm aware new.instancemethod doesn't exist in python 3 and overloading functions doesn't technically either.

However, I am looking at an old python package which uses new.instancemethod in a script that effectively allows for overloaded functions.

The specific package can be found from this site although I've included what I believe is the relevant section below.

I am using python 3 so I need to convert it into a usable script for python 3. I've used the 2to3 tool and reviewed most of the changes already. However, I am stuck on the below which I can't figure out what to replace new.instancemethod with.

class overloaded:
    ...

    def __get__(self, obj, type=None):
        if obj is None:
            return self
        return new.instancemethod(self, obj)

Class overloaded is used in front of __init__ as a decorator which is posing no problems, but it is a problem when it is used in front of a method because obj is no longer None.

The reason I need this, is because a) it is useful and b) because I am currently translating the out-of-date IbPy package from 2.56 to 3.x. The IbPy package is basically the Java API of Interactive Brokers translated into Python.

The main method that @overloaded is placed in front of can be found below:

@overloaded
@synchronized(mlock)
def eConnect(self, host, port, clientId):
    host = self.checkConnected(host)
    if host is None:
        return
    try:
        socket = Socket(host, port)
        self.eConnect(socket, clientId)
    except Exception as e:
        self.eDisconnect()
        self.connectionError()

Note that @synchronize is just a decorator that forces synchronization of multiple functions. The code is short and can be found here, although I don't believe it is relevant for my issue.

So after that long explanation, how would I get return new.instancemethod(self, obj) to look more python 3? I can't seem to wrap my head around what is happening despite reading about it for all of last night and this morning. I've tried many things already, and I think I just lack the understanding in python of how to handle this.

Any advice would be greatly appreciated. Thanks!

score 1 · Accepted Answer · edited May 23 '17 at 12:16

1

types.MethodType should be used instead of new.instancemethod

or you can get instancemethod from any class:

instancemethod = type(Anyclass.method)

where method is any class method

Adding a Method to an Existing Object Instance

edited May 23 '17 at 12:16

Community

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answered Apr 28 '13 at 19:45

ndpu

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funny I used that earlier but must have switched the arguments because it didn't work that time. Anyways it works. Thanks! – Terence Chow Apr 28 '13 at 20:08

new.instancemethod convert to python 3.3 in overloading script

1 Answers1