A Python pickle would be comparable to a MATLAB .mat file. For Mathematica, you'd typically either make a text file containing Mma code (e.g., with the Save fun

A Python pickle would be comparable to a MATLAB .mat file. For Mathematica, you'd typically either make a text file containing Mma code (e.g., with the Save function) or write binary data in some proprietary Mma form with DumpSave. I'd guess the latter is faster and makes smaller files, but I've never checked. More realistically, though, in any situation where you're seriously trying to decide between Mma, MATLAB and Python, your data will be coming in in some "neutral" format and you'll need to parse it. So the Mma and Python code is much more realistic than the MATLAB code. (But perhaps when the author actually needed to do this, it happened that the previous step had been done in MATLAB. That would explain taking input as a .mat file.)