Package rdkit :: Package VLib :: Package NodeLib :: Module SmartsMolFilter

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# Source Code for Module rdkit.VLib.NodeLib.SmartsMolFilter

      1  #  $Id$
      2  #
      3  #  Copyright (C) 2003 Rational Discovery LLC
      4  #     All Rights Reserved
      5  #
      6  from rdkit import RDConfig
      7  import sys,os,types
      8  from rdkit import Chem
      9  from rdkit.VLib.Filter import FilterNode
     10
     11 -class SmartsFilter(FilterNode):
     12    """ filter out molecules matching one or more SMARTS patterns
     13
     14    There is a count associated with each pattern. Molecules are
     15    allowed to match the pattern up to this number of times.
     16
     17    Assumptions:
     18
     19      - inputs are molecules
     20
     21
     22    Sample Usage:
     23      >>> smis = ['C1CCC1','C1CCC1C=O','CCCC','CCC=O','CC(=O)C','CCN','NCCN','NCC=O']
     24      >>> mols = [Chem.MolFromSmiles(x) for x in smis]
     25      >>> from rdkit.VLib.Supply import SupplyNode
     26      >>> suppl = SupplyNode(contents=mols)
     27      >>> ms = [x for x in suppl]
     28      >>> len(ms)
     29      8
     30
     31      We can pass in SMARTS strings:
     32      >>> smas = ['C=O','CN']
     33      >>> counts = [1,2]
     34      >>> filt = SmartsFilter(patterns=smas,counts=counts)
     35      >>> filt.AddParent(suppl)
     36      >>> ms = [x for x in filt]
     37      >>> len(ms)
     38      5
     39
     40      Alternatively, we can pass in molecule objects:
     41      >>> mols =[Chem.MolFromSmarts(x) for x in smas]
     42      >>> counts = [1,2]
     43      >>> filt.Destroy()
     44      >>> filt = SmartsFilter(patterns=mols,counts=counts)
     45      >>> filt.AddParent(suppl)
     46      >>> ms = [x for x in filt]
     47      >>> len(ms)
     48      5
     49
     50      Negation does what you'd expect:
     51      >>> filt.SetNegate(1)
     52      >>> ms = [x for x in filt]
     53      >>> len(ms)
     54      3
     55
     56
     57    """
     58 -  def __init__(self,patterns=[],counts=[],**kwargs):
     59      FilterNode.__init__(self,func=self.filter,**kwargs)
     60      self._initPatterns(patterns,counts)
     61
     62 -  def _initPatterns(self,patterns,counts):
     63      nPatts = len(patterns)
     64      if len(counts) and len(counts)!=nPatts:
     65        raise ValueError('if counts is specified, it must match patterns in length')
     66      if not len(counts):
     67        counts = [1]*nPatts
     68      targets = [None]*nPatts
     69      for i in range(nPatts):
     70        p = patterns[i]
     71        c = counts[i]
     72        if type(p) in types.StringTypes:
     73          m = Chem.MolFromSmarts(p)
     74          if not m:
     75            raise ValueError('bad smarts: %s'%(p))
     76          p = m
     77        targets[i] = p,c
     78      self._patterns = tuple(targets)
     79
     80 -  def filter(self,cmpd):
     81      neg = self.Negate()
     82      res = 0
     83      #sys.stderr.write('\tFILTER: %s\n'%(Chem.MolToSmiles(cmpd)))
     84      for patt,count in self._patterns:
     85        ms = cmpd.GetSubstructMatches(patt)
     86        nMatches = len(ms)
     87        if nMatches >= count:
     88          # this query is an or, so we short circuit true:
     89          res = 1
     90          break
     91      return res
     92
     93  #------------------------------------
     94  #
     95  #  doctest boilerplate
     96  #
     97 -def _test():
     98    import doctest,sys
     99    return doctest.testmod(sys.modules["__main__"])
    100
    101
    102  if __name__ == '__main__':
    103    import sys
    104    failed,tried = _test()
    105    sys.exit(failed)
    106