Reverted read_raw to original function. Created _read_raw using bytearray for efficiency in Python 3 and changed all calls of read_raw to _read_raw.
Reverted read_raw to original function.
Created _read_raw using bytearray for efficiency in Python 3 and changed all calls of read_raw to _read_raw.

hgrecco/pyvisa,pyvisa/pyvisa