def test_last_o_skipped(self):
smiles = "NC(CCCN)C(=O)O"
assert methylate(smiles, "O") == smiles
def test_o(self):
front = "NC(CCCC(=O)O"
back = ")C(=O)O"
assert methylate(front + back, "O") == front + "(C)" + back
def test_ring_unmethylated(self):
ring = "Nc1cccc1C(=O)O"
assert methylate(ring, "C") == ring
def test_c(self):
front = "NC(C(=O)C"
back = ")C(=O)O"
assert methylate(front + back, "C") == front + "(C)" + back