A small gpiozero extension to include the 74HCT595 shift register family in gpiozero.
Assuming Pin 9 is connected to SH_CP (clock), Pin 10 is connected to ST_CP (show/latch), and Pin 11 is connected to DS (data)
from shiftregister import ShiftRegister
register = ShiftRegister(9, 10, 11)
register.show() # Clear to zero
register.shift(1)
register.shift(0)
register.show()