Comment by dekhn
2 days ago
I wrote a very simple SMILES parser using pyparsing https://github.com/dakoner/smilesparser/tree/master I wouldn't say it's intended for production work, but it has been useful in situations where I didn't want to pull in rdkit.
I see you include the dot disconnect "." as part of the Bond definition.
You also define Chain as:
I believe this means your grammar allows the invalid SMILES C=.N