def remove_inchi_prefix(string):
"""
Splits off the 'InChI=1S' or 'InChI=1' layer of an InChI
and returns the last part.
"""
if not INCHI_PREFIX in string:
raise InchiException('Not a valid InChI: {}'.format(string))
return re.split(r"(InChI=1+)(S*)/", string)[-1]
def __new__(self, inchi):
if not INCHI_PREFIX in inchi:
raise InchiException('Not a valid InChI: {}'.format(inchi))
return str.__new__(self, remove_inchi_prefix(inchi))