def compound_interest(principle, rate, years):
if principle > 0 and rate > 0 and years > 0:
interest = 0.0
x = principle
old_principle = principle
for i in range(years):
interest = (x * rate * 1)/100
x = x + interest
comp_interest = x - old_principle
return comp_interest
else:
return(0)
i did not understand the program. please help