As a python coder that has changed to Pharo I can tell you that the answer to your questions is "no". Its actually much better because cpython is not a live coding environment but Pharo is.
iPython tries to compensate , Pharo of course lacks some of the features of iPython but overall Pharo's ability to do true live coding really shines here. Live coding means the ability to code your application while it runs without every need to stop it and restart it to correct an error.
Pharo lacks the existence of a pure mathematical library like numpy however it offers not only Nativeboost that gives full access to C libraries similar to ctypes for Python , Nativeboost also is an inline assembler. In theory that means access to raw speed.
Matplotlib I am not very familiar with but Pharo has a set of library called Moose which contain several libraries for visualisations one of them is Roassal which is easy enought to use for several kinds of Graphs and illustrations, there is even Roassal3d if 3d graphics is your thing.
