How many "versions" of the Supreme Court have there been?

Just something silly to have spent a few hours creating. The impetus was that all of the charts, graphs, and tables I found on wikipedia and supremecourt.gov that show the composition of the US Supreme Court throughout history, do not provide a straightforward way to know how many different "compositions" (I'd say "era", but that has an established meaning as being the time period for which a particular chief justice was in office) the court has had over the years. (That is, how many different groups of appointed-for-life justices have existed, not just how many eras of individual Chief Justices have existed, which is easy enough to find.) Plus, it gave me a chance to write something using pandas dataframes. As is obvious, "scope creep" plays a roll and now it displays other information in other ways and the data I wanted that drove me to write a small program is pushed to the very bottom of the screen. :-)

Note that it may take a while to complete execution due to literally iterating through every day from start date to end date (up to some 86k days). Probably not optimal. It now only iterates through each justice's days in office, checking for other justices in office those days. If it's not optimal, I'm not concerned; execution time for all the court's history went from 3 minutes to < 3 seconds after making this change. Upon completion the output will be a table showing each year in the range requested and the judges on the bench at the time (small rows containing just a year indicate a new year is starting and if there are several in a row it means the composition didn't change from year to year.) I also did away with that (by oversight) when optimizing for speed.

Oh! The number I was originally looking to find - the entire reaason I started working on this problem - will be shown at the bottom of the page, after the table. If you just came to know that answer from the first justice to today: as of this writing there have been 210 different groups of judges comprising the US Supreme Court. If you select any sort of date range, the total for that period will be displayed.

Start search in year:		(leave blank to start at the beginning)
End at year:		(leave blank to go all the way to the present day lineup)
Go!	note that the greater the timespan, the longer it will take to calculate. For the entire history of the court (both fields blank) it should complete in 1-3 minutesseconds.