cplex specifies 3 output streams: log, error, warning and results. You can disable the output with the commands. set_xxx_stream(None). In your example,
prob.set_log_stream(None)
prob.set_error_stream(None)
prob.set_warning_stream(None)
prob.set_results_stream(None)
will disable all output. You can also specify an output file, instead of None. There are also several parameters that you can set to control the verbosity of the cplex output, but this is the best way to prevent cplex from printing anything.