Remove "new" from DCD module

[richardjgowers]

The DCD coordinate module uses the new module which is deprecated since 2.6.

https://docs.python.org/2/library/new.html

The imports to the DCD Reader class from the external C code need rejigging slightly to not use new.

This is blocking #260

[kain88-de]

I'm not very familiar with new what rejingling would be required? To me it looks like I can make them simple class members with.

def _read_dcd_header(*args):
    return _dcdmodule.__read_dcd_header(*args)

Or does new something else then just adding a function to the class?

[orbeckst]

@kain88-de , do you want to give it a try? Once the unit tests pass and new is gone you're done ;-).

[richardjgowers]

Sorry, I used a word that isn't a word, to rejig is to rearrange.

Basically the usage of module "new" needs removing, but no functionality
needs changing

On 11:42PM, Tue, 4 Aug 2015 Oliver Beckstein [email protected]
wrote:

@kain88-de https://github.com/kain88-de , do you want to give it a try?
Once the unit tests pass and new is gone you're done ;-).

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#337 (comment)
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[kain88-de]

Ok my naive approach doesn't work. This is because you found a way to define a python class in pure python AND C. Which is either very much discouraged or not allowed anymore, I could find any information how to do this without new.

Most of the methods in dcd.c assume that they are already an instance method. Which means I can't call them as normal functions. This would mean all of these function need to be refactored to be called as single functions. Then my approach will work. I don't have much experience writing raw cpython. For me a rewrite in cython is better but that would take a while.

[richardjgowers]

I think new was made obsolete in favour of types, maybe if you used types.MethodType? Something like DCDReader.method = types.MethodType(_dcd.function)

https://docs.python.org/2/library/types.html#types.MethodType