I am not sure what the expected behavior is. Based on the code on pydoc.py we can find:
def getdoc(object):
    """Get the doc string or comments for an object."""
    result = inspect.getdoc(object) or inspect.getcomments(object)

So if the doc string is not found it searches for the lines of comments immediately preceding the object's source code.

This is why the example from Anupama returns the preceding comment on both python2.7 and python3.5 (not only on python2.7).

@rhettinger this seems like a deliberate decision to add as help documentation the preceding comment if the docstring is not found. What were you expecting? Should this be changed?