Along the lines of Seth's answer, the pandas library fits in a weird place as a comparison to R, as pandas provides two additional data containers to Python (Series & DataFrame), as well as additional useful data processing functionality around handling of missing data, set comparisons, & vectorization. read more
With visualization in Python, there is usually one main way to do something, whereas in R, there are many packages supporting different methods of doing things (there are at least a half dozen packages to make pair plots, for instance). read more