This is a Python library for communicating with the BK Precision 1696 power supply via its serial interface. You can control the supply's parameters and take voltage/current readings.
For example:
import psup
with psup.Supply() as sup:
sup.voltage(1.3)
volts, amps = sup.reading()
print '%f V, %f A' % (volts, amps)
For more details, see my blog post about a setup using this library to measure the dynamic power of a smartphone.