Install it with pip install perfcount.
There are multiple decorators included for testing in the library, including perf.perf, perfcount.perf_ns, perfcount.shouldtake, and perfcount.timeout. The perfcount.time_this_program module can be imported to time the program from the time of importing the perfcount.time_this_program module to interpreter exit.
The command perftcount can be used to measure execution time of a command. Ex. perfcount python script.py.