Return Value to Script?

[tottka]

Hi,
Thank you for putting this on the web. Your documentation is great.
I've written a small script to get the value from WU & push it out to other devices in my network but can't seem to grab the returned value. This is what I have
import os
os.system("pywu fetch api-key 12345")
a = os.system("pywu -f 1 current temp_f")
print(a)

The results are
50 from pywu as show on console
0 from the value of a

Is this even possible?
thanks