I recently discovered the UHD Python API for controlling USRPs. It is really nice, and the performance isn't too shabby, when you use numpy for signal processing. You have nearly all of the UHD C API available on Python, and some additional high level calls, such as recv_num_samples. We're currently in the process of implementing an open source software defined ionosonde using just the UHD Python API. Stay tuned. Here's a simple example, which implements a spectrum analyzer. We've been using this to test that our system meets the frequency licensing requirements: #!/usr/bin/env python3 import numpy as n import uhd import scipy.signal as ss import time import matplotlib.pyplot as plt import h5py def acquire_spectrum(freq=12.5e6,                      sample_rate=25e6,                      N=250000,                       N_windows=10000,                       subdev="A:A",                      ofname="spec.h5"):     usrp = uhd