#! /usr/bin/env python
#
def isbn_digit_to_i4 ( c ):

#*****************************************************************************80
#
## ISBN_DIGIT_TO_I4 converts an ISBN digit to an I4.
#
#  Discussion:
#
#    The characters '0' through '9' stand for themselves, but
#    the character 'X' or 'x' stands for 10.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    16 September 2015
#
#  Author:
#
#    John Burkardt
#
#  Parameters:
#
#    Input, character C, the ISBN character code to be converted.
#
#    Output, integer VALUE, the numeric value of the character
#    code, between 0 and 10.  This value is returned as -1 if C is
#    not a valid character code.
#
  if ( c == '0' ):
    value = 0
  elif ( c == '1' ):
    value = 1
  elif ( c == '2' ):
    value = 2
  elif ( c == '3' ):
    value = 3
  elif ( c == '4' ):
    value = 4
  elif ( c == '5' ):
    value = 5
  elif ( c == '6' ):
    value = 6
  elif ( c == '7' ):
    value = 7
  elif ( c == '8' ):
    value = 8
  elif ( c == '9' ):
    value = 9
  elif ( c == 'X' or c == 'x' ):
    value = 10
  else:
    value = -1

  return value

def isbn_digit_to_i4_test ( ):

#*****************************************************************************80
#
## ISBN_DIGIT_TO_I4_TEST tests ISBN_DIGIT_TO_I4.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    16 September 2015
#
#  Author:
#
#    John Burkardt
#
  import numpy as np
  import platform

  c_test = np.array ( [ \
    '0', '1', '2', '3', '4', \
    '5', '6', '7', '8', '9', \
    'X', 'x', 'Y', '*', '?', \
    ' ' ] )

  print ( '' )
  print ( 'ISBN_DIGIT_TO_I4_TEST' )
  print ( '  Python version: %s' % ( platform.python_version ( ) ) )
  print ( '  ISBN_DIGIT_TO_I4 converts an ISBN digit to an I4' )
  print ( '' )

  for i in range ( 0, 16 ):
    c = c_test[i]
    i4 = isbn_digit_to_i4 ( c )
    print ( '  "%c"      %2d' % ( c, i4 ) )
#
#  Terminate.
#
  print ( '' )
  print ( 'ISBN_DIGIT_TO_I4_TEST:' )
  print ( '  Normal end of execution.' )
  return

if ( __name__ == '__main__' ):
  from timestamp import timestamp
  timestamp ( )
  isbn_digit_to_i4_test ( )
  timestamp ( )