#------------------------------------------------------------------------------
#  DecimalRounding.py
#
#  Illustrate the quantize function in the decimal.Decimal class. See
#  quantize() at: https://docs.python.org/3/library/decimal.html
#
#------------------------------------------------------------------------------
from decimal import *

def main():

   N = 12

   getcontext().prec = N
   x = Decimal('2.192853746')
   print()
   print(x)
   print(x.quantize(Decimal('0.000'))) # 3 digits to the right of the '.'
   print(x.quantize(Decimal('0E-3')))  # same thing in scientific notation
   print()

   for k in range(1,N):  # try going to N+1. Observe InvalidOperation.
                         # number of digits k must be < precision N

      y = Decimal('0E-'+str(k))
      print(x)  # number to be rounded
      print(y)  # number giving model rounding
      print(x.quantize(y, rounding=ROUND_DOWN),      '\t round down (truncate)')
      print(x.quantize(y, rounding=ROUND_UP),        '\t round up')
      print(x.quantize(y, rounding=ROUND_HALF_DOWN), '\t round half down')
      print(x.quantize(y, rounding=ROUND_HALF_UP),   '\t round half up')
      print()
   # end

      
# end

#------------------------------------------------------------------------------
if __name__=='__main__':

   main()

# end