Allow SD card to store python pickle objects

[robmarkcole]

Feature Request 🚀

Hi
I am collecting data from a bunch of sensors, placing it in a dict, then dumping the dict as a json string to a text file that's saved to the SD card following the docs example. I then have to load the data into pandas on my laptop, it's all a but tedious. Much nicer would be if I could just dump straight into a dataframe that was then pickled on the SD card, and could then be loaded straight into pandas