import ast
import tokenize
import io


source = '"""\n"""\n' # bug appears also with indentation, eg. 'if True:\n    """\n    """\n'
root = ast.parse(source)


# some ast nodes have -1 in col_offset field
print("\nNODES:")
for node in ast.walk(root):
    if "lineno" in node._attributes:
        print(node, node.lineno, node.col_offset)


# no token has -1 in column field
print("\nTOKENS:")
for tok in tokenize.tokenize(io.BytesIO(source.encode('utf-8')).readline):
    print(tok)