Re: [Rdkit-discuss] SD Tag Reording

[Greg L. <gre...@gm...>]

Dear Matt,

On Thu, Feb 27, 2014 at 8:09 PM, Matthew Lardy <ml...@gm...> wrote:

>
> I've noticed that I am unable to reorder SD tags in RDKit.  It appears
> that no matter what I try, they get reordered in alphabetical order.  Is
> anyone else experiencing this behaviour?
>

Here's the default behavior, which is what you describe:

In [1]: from rdkit import Chem
In [2]: from StringIO import StringIO
In [3]: m1 = Chem.MolFromSmiles('C')
In [4]: m1.SetProp('CProp','c')
In [5]: m1.SetProp('BProp','b')
In [6]: m1.SetProp('AProp','a')
In [7]: sio=StringIO()
In [8]: w = Chem.SDWriter(sio)
In [9]: w.write(m1)
In [10]: w.flush()
In [11]: print sio.getvalue()

     RDKit

  1  0  0  0  0  0  0  0  0  0999 V2000
    0.0000    0.0000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
M  END
>  <AProp>  (1)
a

>  <BProp>  (1)
b

>  <CProp>  (1)
c

$$$$


You can, however provide a list of property names to be written out. If you
do this, your order will be obeyed:

In [17]: sio=StringIO()
In [18]: w = Chem.SDWriter(sio)
In [19]: w.SetProps(('BProp','CProp','AProp'))
In [20]: w.write(m1)
In [21]: w.flush()
In [22]: print sio.getvalue()

     RDKit

  1  0  0  0  0  0  0  0  0  0999 V2000
    0.0000    0.0000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
M  END
>  <BProp>  (1)
b

>  <CProp>  (1)
c

>  <AProp>  (1)
a

$$$$


I hope this helps,
-greg