Put all of the arguments in a text file, one per line. Then,
xargs python myprogram.py < argslist.txt
xargs reads in a list of tab, newline, or space-delimited arguments from standard in, and then feeds it to the utility to be executed after additional arguments on the command line.
So where here we have
xargs utility arg1 < extraArgs.txt,
xargs is going to execute
arg1 as the first argument and then since we are redirecting the contents of
xargs' standard in stream, it will append the arguments after