Try this snippet:
miles = Rods * 0.003125
print("Distance in Miles = {:.20f}".format(miles))
This code does the calculation first and formats the answer such that it is displayed in 20 decimal places. For displaying only 10 decimal places change to .10f, for 2 decimal places change to .2f and so on.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…