Cannot printpf with a pf result

[hoangluong]

Hello,

When I tried the source code as in the tutorial http://www.pypower.org/usage.html, I got an error with printpf as follows
In [5]: printpf(r)

Traceback (most recent call last):
File "", line 1, in
File "/ufs/luong/.local/lib/python2.7/site-packages/PYPOWER-4.0.1-py2.7.egg/pypower/printpf.py", line 139, in printpf
i2e = bus[:, BUS_I].astype(int)
TypeError: 'NoneType' object has no attribute 'getitem'

Note that if r is a result returned from a runopf then there is no problem printing it. But if r is a result return from runpf then I got the above error message.

[rwl]

The run*() API should be more consistent. runopf returns a single case containing the results. runpf returns a (r, success) tuple that indicates if the problem was solved successfully. Sorry that the documentation is not more clear.