1__doc__ = u"""
2>>> try: exc()
3... except IndexError:
4...     if IS_PY3:
5...         print(isinstance(sys.exc_info()[1].__context__, ValueError))
6...     else:
7...         print(True)
8True
9"""
10
11import sys
12IS_PY3 = sys.version_info[0] >= 3
13
14def exc():
15    try:
16        raise ValueError
17    except ValueError:
18        raise IndexError
19