Compound interest function

compounding.py

""" Compute compound interest given a rate, period and periodic rate increase

Args:
    start: starting number
    periods: compounding period
    rate_growth: compounding rate growth rate
    rate: starting compounding rate
    
Returns:
    Final compounded value
"""

def compound(start, periods, rate_growth=.10, rate=.015):
    t = start
    r = rate
    for x in range(periods):
        t = t + (t * r)
        r = r + (r * rate_growth)
    return t

def table(start, period, rate, growth):
     for x in range(period):
         p2 = compound(start, x, rate=rate, rate_growth=growth)
         p1 = compound(start, x - 1, rate=rate, rate_growth=growth)
         yield {'year': x, 'total':p2,  'income':p2 - p1}