I am using PyCharm 2016.2.1 . When I try to view a Pandas dataframe through the newly added feature \'View as DataFrame\' in the debugger, this works as expected for a small
For the sake of completeness: I face the same problem, due to the fact that some elements in the index of the dataframe contain a question mark '?'. One should avoid that too, if you still want to use the data viewer. Data viewer still worked, if the index strings contain hashes or less-than/greather-than signs though.