#  Interest.py  (c) Kari Laitinen

#  http://www.naturalprogramming.com

#  2006-04-18  File created.
#  2022-12-16  Converted to Python 3.

#  The initialized table below is a tuple. A tuple in Python is
#  an initialized sequence of data that is immutable, i.e.,
#  you cannot add new items to a tuple or replace items in a 
#  tuple once the tuple is created.

compound_interest_table  =  \
   (
     ( 5.00, 10.25, 15.76, 21.55, 27.63, 34.01, 40.71, 47.75 ),
     ( 6.00, 12.36, 19.10, 26.25, 33.82, 41.85, 50.36, 59.38 ),
     ( 7.00, 14.49, 22.50, 31.08, 40.26, 50.07, 60.58, 71.82 )
   )

print( "\n This program calculates the compound interest" \
      "\n for a given sum of money (principal). \n" \
      "\n  Give the loan amount: ", end="" )

given_sum_of_money  =  float( input() ) 

print( "\n  Give the interest percentage ( 5, 6, or 7): ", end="" )

interest_percentage  =  int( input() )

print( "\n  Give the loan period in years ( max. 8 ): ", end="" )

loan_period_in_years  =  int( input() )

print( "\n  For a loan of %.2f you must pay "  \
      "\n  %.2f as compound interest after %d years."  %  \
      ( given_sum_of_money,  
        ( given_sum_of_money / 100.0 ) *
            compound_interest_table[ interest_percentage - 5 ]
                                   [ loan_period_in_years - 1 ],
        loan_period_in_years  ) )


#  The table above could be defined as a list and the program
#  would operate in the same way as it operates now. The table
#  could be defined as a list by using brackets instead of 
#  parentheses in the following way:

#compound_interest_table  =  \
#   [
#     [ 5.00, 10.25, 15.76, 21.55, 27.63, 34.01, 40.71, 47.75 ],
#     [ 6.00, 12.36, 19.10, 26.25, 33.82, 41.85, 50.36, 59.38 ],
#     [ 7.00, 14.49, 22.50, 31.08, 40.26, 50.07, 60.58, 71.82 ]
#   ]