Fix "documentation is not available.", refactor get_commands

[samuel-w]

I found this bug while testing #130. Added a testcase for the future.

Sped up get_commands about 5x, tested with

import time
start_time = time.time_ns()
for i in range(100):
    get_commands()
print("Time: {}".format(time.time_ns()-start_time))

Fixes #131