#! /usr/bin/env python
#
def s_to_isbn_digits ( s, n ):

#*****************************************************************************80
#
## S_TO_ISBN_DIGITS extracts N ISBN digits from a string.
#
#  Discussion:
#
#    The string may include spaces, letters, and dashes, but only the
#    digits '0' through '9' and 'X' will be extracted.
#
#  Example:
#
#    S  => 34E9X-70.6
#    N  => 5
#    D <=  (/ 3, 4, 9, 10, 7 /)
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license. 
#
#  Modified:
#
#    16 September 2015
#
#  Author:
#
#    John Burkardt
#
#  Parameters:
#
#    Input, string S, the string.
#
#    Input, integer N, the number of digits to extract.
#
#    Output, integer DVEC(N), the extracted digits.
#
  import numpy as np
  from ch_is_isbn_digit import ch_is_isbn_digit
  from isbn_digit_to_i4 import isbn_digit_to_i4
  from sys import exit

  s_len = len ( s )

  s_pos = 0
  d_pos = 0

  dvec = np.zeros ( n, dtype = np.int32 )

  while ( d_pos < n ):

    if ( s_len <= s_pos ):
      print ( '' )
      print ( 'S_TO_ISBN_DIGITS - Fatal error!' )
      print ( '  Could not read enough data from string.' )
      error ( 'S_TO_ISBN_DIGITS - Fatal error!' );

    c = s[s_pos]
    s_pos = s_pos + 1

    if ( ch_is_isbn_digit ( c ) ):
      dvec[d_pos] = isbn_digit_to_i4 ( c )
      d_pos = d_pos + 1

  return dvec

def s_to_isbn_digits_test ( ):

#*****************************************************************************80
#
## S_TO_ISBN_DIGITS_TEST tests S_TO_ISBN_DIGITS.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    16 September 2015
#
#  Author:
#
#    John Burkardt
#
  import platform
  from i4vec_print import i4vec_print

  print ( '' )
  print ( 'S_TO_ISBN_DIGITS_TEST' )
  print ( '  Python version: %s' % ( platform.python_version ( ) ) )
  print ( '  S_TO_ISBN_DIGITS: string -> ISBN digit vector' )
  
  s = '34E9X-70.6'
  print ( '' )
  print ( '  Test string: "%s"' % ( s ) )
  n = 5
  dvec = s_to_isbn_digits ( s, n )
  i4vec_print ( n, dvec, '  Extracted 5 digits:' )

  s = '34E9X-70.6'
  print ( '' )
  print ( '  Test string: "%s"' % ( s ) )
  n = 7
  dvec = s_to_isbn_digits ( s, n )
  i4vec_print ( n, dvec, '  Extracted 7 digits:' )
#
#  Terminate.
#
  print ( '' )
  print ( 'S_TO_ISBN_DIGITS_TEST' )
  print ( '  Normal end of execution.' )
  return

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