Check fail after run pass

I've ran into next fail.

/home/site/checkio/runners/py32.py:255: DeprecationWarning: cgi.escape is deprecated, use html.escape instead, error = u'TypeError: {0} is wrong data type'.format(cgi.escape(str(type(result)))),TypeError: <class 'list'> is wrong data type

or

TypeError: <class 'list'> is wrong data type

Fail:undefined("\n001203\n023001\n100220")

When I run it explicitly as it appears in check:

print("Example:")
print(buttons("\n001203\n023001\n100220"))
exit(0)

Everything is OK

Example:
[8, 4, 4, 1]

Process finished with exit code 0

I have no idea whylist is wrong.