I wrote a very simple SMILES parser using pyparsing https://github.com/dakoner/s... | Hacker News

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		dekhn 3 days ago \| parent \| context \| favorite \| on: Parsing Chemistry 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.

dalke 3 days ago [–]

I see you include the dot disconnect "." as part of the Bond definition.

You also define Chain as:

  Chain <<= pp.Group(pp.Optional(Bond) + pp.Or([Atom, RingClosure]))

I believe this means your grammar allows the invalid SMILES C=.N

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