Something wroing in rpy2 / R interface in Official Guide
In Latest Version of Pandas, the code explanation is kind of misleading due to the lack of rpy2 dependency. Please see png below:
![error](https://user-images.githubusercontent.com/16098658/45799203-44097700-bcdf-11e8-9ab6-09428b1ba8d3.JPG)

Here is the link: 
https://pandas.pydata.org/pandas-docs/stable/r_interface.html