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python plotting and image viewing library with equivalent of MATLABs datatips

Currently, I use MATLAB extensively for analyzing experimental scientific data (mostly time traces and images). However, again and again I keep running into fundamental problems with the MATLAB language and I would like to make the switch to python. One feature of matlab is holding me back however: its ability to add datatips to plots and images.
For a line plot the datatip is a window next to one of the data points that shows its coordinates. This is very useful to quickly see where datapoints are and what their value is. Of course this can also be done by inspecting the vectors that were used to plot the line, but that is slightly more cumbersome and becomes a headache when trying to analyze loads of data. E.g. let's say we quickly want to know for what value of x, y=0.6. Moving the datatip around will give a rough estimate very quickly.
For images, the datatip shows the x and y coordinates, but also the greyscale value (called index by MATLAB) and the RGB color. I'm mainly interested in the greyscale value here. Suppose we want to know the coordinates of the bottom tip of the pupil of the cat's eye. A datatip allows to simply click that point and copy the coordinates (either manually or programmatically). Alternatively, one would have to write some image processing script to find this pixel location. For a one time analysis that is not worthwhile.
The plotting library for python that I'm most familiar with and that is commonly called the most flexible is matplotlib. An old stock overflow question seems to indicate that this can be done using mpldatacursor and another module seems to be mplcursors. These libraries do not seem to be compatible with Spyder, however, limiting their usability. Also, I imagine many python programmers would be using a feature like datatips, so it seems odd to have to rely on a 3rd party module.
Now on to the actual question: Is there any module (or simple piece of code that I could put in my personal library) to get the equivalent of MATLAB's datatips in all figures generated by a python script?

Programmatically altering stl CAD files with Python

I have many stl CAD files for 3D printing and I was wondering how I can manipulate an individual CAD file by making a simple change programatically. Like if I want to double the dimensions of everything in the CAD file, how could I accomplish this in python? I could convert it to gcode if that makes things simpler.
I have come across FreeCad but I am not sure if this is the easiest and best way of programmatically altering CAD files. I also wanted an option that allows for freedom of manipulation beyond just size, maybe also seeing how I can programmatically alter the shape of the CAD file.

Well to be precise, STL files are even not meshes, but triangles soups. Which means that triangles are even not connected to each other (well they need to be adjacent to be used by software generatif g-code, but no obligation else)
just for clarification: g-code format is just a sequence of instructions for the machines (3d-printers, etc) so it's very good for printers, but also certainly the worst format to manipulate geometry.
one solution
you can use the python pymadcad module to deal with STL files
So for simple transformation operations (such as scale, translation etc)
from madcad import *
part = read('path/to/your_file.stl')
transformed = part.transform(mat3(2)) # scale by a factor 2 (diagonal matrix of 2)
write(transformed, 'path/to/output_file.stl')
If you need more complex operations (such as booleans, chamfers, etc) you will need to make the triangle connected again before the desired operations.
from madcad import *
part = read('path/to/your_file.stl')
part.mergeclose() # merge points at the same location
# your desired operations (example)
transformed = union(part, icosphere(vec3(1,1,1), 3.)) # add a sphere a diameter 3
write(transformed, 'path/to/output_file.stl')
note
pymadcad is internally using numpy-stl to import stl files, if you need only basic manipulations you can also only install that one

STL files are meshes. Their exterior is defined by triangulated surfaces. Meshes are notoriously difficult to modify after the fact. That's why you always want to save your designs in the native format and also in an open solid format like .STP or .IGES.
That said, simple scaling of a mesh is pretty easy and can be done trivially in FreeCAD.
You can do it in the gui in the mesh design workbench or through python. Here's a post about that:
https://forum.freecadweb.org/viewtopic.php?t=9109#p74047
FreeCAD also has some tools to convert a mesh into a solid. Results are usually less than spectacular but might be good enough depending on your needs. Search on the FreeCAD forum for posts about converting or look here: https://wiki.freecadweb.org/FreeCAD_and_Mesh_Import
Gcode doesn't say anything about the model itself. It specifies where a tool should move so it's just a series of directives that move a tool from place to place at a given speed. Going from Gcode to a model that you can edit is pretty difficult or impossible.

.asc viewer using Kivy

I want to develop a 3D file viewer in kivy and python that reads and displays .asc mesh files of the format:
x1,y1,z1
x2,y2,z2
........
xi,yi,zi
What I have thought so far is to use a method similar to beginShape() of Processing so as to begin drawing a 3D shape then use a for-loop to append each point respectively.
I have also found that kivy example which parses .obj files and then displays them. Do you have any ideas on how can I make a similar ascparser and try to display my files?
Any help is greatly appreciated

I have also found that kivy example which parses .obj files and then displays them. Do you have any ideas on how can I make a similar ascparser and try to display my files?
Your best strategy at the moment is probably to read the objparser and try to understand what it is doing. The important thing is building a list of points and normals, which are passed to opengl via a Mesh with a custom vertex_format and custom shaders. In principle it wouldn't be very hard to do the same thing for your own filetype just by comparison with the .obj code, though you will need some understanding of what's going on (you can read about opengl and read the kivy source, if you haven't already) to make significant changes.
This is really an advanced topic right now, Kivy has very few pre-built wrappers to 3d opengl rendering. The backend is fully capable (so the 3d rendering example isn't that complex, for instance), but you probably do need some understanding of what's going on to accomplish things like your own task.
There are also a few other examples of 3d rendering in Kivy, which you might find helpful. nskrypnik has several repositories doing just this (see kivy-trackball, kivy-3dpicking, kivy-rotation3d), and seems to have begun implementing a proper 3d api in the kivy3 repo, though this is not complete and I suggest it as something you can learn about by reading, not something that can necessarily do what you want right now. The other nice example I've seen is a 3d inspector POC by tito, though it's just a proof of concept and not a polished product.

3D Animation of Fractals

I'm giving a presentation on Fractal Antennas (take a look at my previous threads) in November and I wanted to incorporate some animation to make my presentation easier to visualize the content I am referring to. Most of these animations would be relatively short, probably a minute long at the most. There are a few animations that would be fantastic to have:
Fractal Mountains - The animation continues to add new iterations that depict the complex features of a mountain range.
Fractal Koch Curve - The animation begins with an initiator (triangle) and adds new iterations. Either I slowly bring in the new fractal that has the next iteration, or I use the same model and users can see the iterations branching outward. I would prefer the latter technique.
Show a fractal. Increase the iteration, while keeping a constant length, to vindicate the fractal shrinking in size.
Show a fractal. Increase the iteration, while keeping a constant size, to vindicate the fractal is increasing it's total perimeter length.
Cell phone animation - show a cell phone that has multiple antennas popping out (they can be simple sketches of lines).
The trouble is, I've never done ANY animation before. In the programs I have already, they generate the coordinates of the fractals, if that can be of some use?
What is the best way to render those animations in the shortest time possible? The presentation is almost 6 weeks away! Blender might be an option, but I have no idea of how to go about this.
There are some great animations in this NOVA video that might give you an idea of what I'm after.
Thanks,
Austin

Personally, I've used VPython to create simple 3D graphics and animations. It's an easy to learn library that's freely available at http://vpython.org/. Since you have the coordinates already, it should be fairly easy to for you to incorporate that into the drawing.
Blender is a bit more complicated, but also incorporates python scripting if you want to spend the time to learn it.
Lastly, referencing some of the YouTube comments: if you use the video just cite it, or email and get permission. If you're not making money on this presentation, then odds are you're going to just fine using the videos.

The easiest would be to use matplotlib.mplot3d. The principle is the same as in the 2D animation described at http://www.scipy.org/Cookbook/Matplotlib/Animations but you will be using the 3D methods described in http://matplotlib.sourceforge.net/mpl_toolkits/mplot3d/tutorial.html.
I teach computer methods in physics and one of the activities is to create a Koch snowflake using Python and matplotlib. I also had a group of students create 3D fractals as their project using Python and Chaco (for interactivity) but using matplotlib instead is pretty straightforward. You can also try mayavi2 which is another 3D plotting library in Python.
If you want to create a movie then you need to save each frame as a graphics file then convert the files into movie using convert (ImageMagick), mencoder, ffmpeg or some other software.
I can probably provide some pseudocode/sample code but I'm too sleepy at the moment (it's 11:30pm from where I am).

How to create a picture with animated aspects programmatically

Background
I have been asked by a client to create a picture of the world which has animated arrows/rays that come from one part of the world to another.
The rays will be randomized, will represent a transaction, will fade out after they happen and will increase in frequency as time goes on. The rays will start in one country's boundary and end in another's. As each animated transaction happens a continuously updating sum of the amounts of all the transactions will be shown at the bottom of the image. The amounts of the individual transactions will be randomized. There will also be a year showing on the image that will increment every n seconds.
The randomization, summation and incrementing are not a problem for me, but I am at a loss as to how to approach the animation of the arrows/rays.
My question is what is the best way to do this? What frameworks/libraries are best suited for this job?
I am most fluent in python so python suggestions are most easy for me, but I am open to any elegant way to do this.
The client will present this as a slide in a presentation in a windows machine.

The client will present this as a slide in a presentation in a windows machine
I think this is the key to your answer. Before going to a 3d implementation and writing all the code in the world to create this feature, you need to look at the presentation software. Chances are, your options will boil down to two things:
Animated Gif
Custom Presentation Scripts
Obviously, an animated gif is not ideal due to the fact that it repeats when it is done rendering, and to make it last a long time would make a large gif.
Custom Presentation Scripts would probably be the other way to allow him to bring it up in a presentation without running any side-programs, or doing anything strange. I'm not sure which presentation application is the target, but this could be valuable information.
He sounds like he's more non-technical and requesting something he doesn't realize will be difficult. I think you should come up with some options, explain the difficulty in implementing them, and suggest another solution that falls into the 'bang for your buck' range.

If you are adventurous use OpenGL :)
You can draw bezier curves in 3d space on top of a textured plane (earth map), you can specify a thickness for them and you can draw a point (small cone) at the end. It's easy and it looks nice, problem is learning the basics of OpenGL if you haven't used it before but that would be fun and probably useful if your in to programing graphics.
You can use OpenGL from python either with pyopengl or pyglet.
If you make the animation this way you can capture it to an avi file (using camtasia or something similar) that can be put onto a presentation slide.

It depends largely on the effort you want to expend on this, but the basic outline of an easy way. Would be to load an image of an arrow, and use a drawing library to color and rotate it in the direction you want to point(or draw it using shapes/curves).
Finally to actually animate it interpolate between the coordinates based on time.
If its just for a presentation though, I would use Macromedia Flash, or a similar animation program.(would do the same as above but you don't need to program anything)