df = pd.DataFrame({'Principle': [20000],
                   'Loan Term Length': [60],
                   'Interest Rate PerTerm': [.005],
                   'Monthly Payment': [386.65603058856544],
                   'Total Amount Paid': (df['Loan Term Length']* df['Monthly Payment']),
                   'Total Interest Paid': (df['Total Amount Paid'] - df['Principle'])})