text: #!/usr/bin/env python
  # -*- coding: UTF-8 -*-
  """
  A commandline tool for parsing RDF in different formats and serializing the
  resulting graph to a chosen format.
  """
  
  import sys
  from optparse import OptionParser
  import logging
  
  import rdflib
  from rdflib import plugin
  from rdflib.store import Store
  from rdflib.graph import ConjunctiveGraph
  from rdflib.namespace import RDF, RDFS, OWL, XSD
  from rdflib.parser import Parser
  from rdflib.serializer import Serializer
  
  from rdflib.util import guess_format
  from rdflib.py3compat import PY3
  
  
  DEFAULT_INPUT_FORMAT = 'xml'
  DEFAULT_OUTPUT_FORMAT = 'n3'
  
  
  def parse_and_serialize(input_files, input_format, guess,
                          outfile, output_format, ns_bindings,
                          store_conn="", store_type=None):
  
      if store_type:
          store = plugin.get(store_type, Store)()
          store.open(store_conn)
          graph = ConjunctiveGraph(store)
      else:
          store = None
          graph = ConjunctiveGraph()
  
      for prefix, uri in list(ns_bindings.items()):
          graph.namespace_manager.bind(prefix, uri, override=False)
  
      for fpath in input_files:
          use_format, kws = _format_and_kws(input_format)
          if fpath == '-':
              fpath = sys.stdin
          elif not input_format and guess:
              use_format = guess_format(fpath) or DEFAULT_INPUT_FORMAT
          graph.parse(fpath, format=use_format, **kws)
  
      if outfile:
          output_format, kws = _format_and_kws(output_format)
          kws.setdefault('base', None)
          graph.serialize(destination=outfile, format=output_format, **kws)
  
      if store:
          store.rollback()
  
  
  def _format_and_kws(fmt):
      """
      >>> _format_and_kws("fmt")
      ('fmt', {})
      >>> _format_and_kws("fmt:+a")
      ('fmt', {'a': True})
      >>> _format_and_kws("fmt:a")
      ('fmt', {'a': True})
      >>> _format_and_kws("fmt:+a,-b") #doctest: +SKIP
      ('fmt', {'a': True, 'b': False})
      >>> _format_and_kws("fmt:c=d")
      ('fmt', {'c': 'd'})
      >>> _format_and_kws("fmt:a=b:c")
      ('fmt', {'a': 'b:c'})
      """
      fmt, kws = fmt, {}
      if fmt and ':' in fmt:
          fmt, kwrepr = fmt.split(':', 1)
          for kw in kwrepr.split(','):
              if '=' in kw:
                  k, v = kw.split('=')
                  kws[k] = v
              elif kw.startswith('-'):
                  kws[kw[1:]] = False
              elif kw.startswith('+'):
                  kws[kw[1:]] = True
              else:  # same as "+"
                  kws[kw] = True
      return fmt, kws
  
  
  def make_option_parser():
      parser_names = _get_plugin_names(Parser)
      serializer_names = _get_plugin_names(Serializer)
      kw_example = "FORMAT:(+)KW1,-KW2,KW3=VALUE"
  
      oparser = OptionParser(
          "%prog [-h] [-i INPUT_FORMAT] [-o OUTPUT_FORMAT] " +
          "[--ns=PFX=NS ...] [-] [FILE ...]",
          description=__doc__.strip() + (
          " Reads file system paths, URLs or from stdin if '-' is given."
          " The result is serialized to stdout."),
          version="%prog " + "(using rdflib %s)" % rdflib.__version__)
  
      oparser.add_option(
          '-i', '--input-format',
          type=str,  # default=DEFAULT_INPUT_FORMAT,
          help="Format of the input document(s)."
          " Available input formats are: %s." % parser_names +
          " If no format is given, it will be " +
          "guessed from the file name extension." +
          " Keywords to parser can be given after format like: %s." % kw_example,
          metavar="INPUT_FORMAT")
  
      oparser.add_option(
          '-o', '--output-format',
          type=str, default=DEFAULT_OUTPUT_FORMAT,
          help="Format of the graph serialization."
          " Available output formats are: %s."
          % serializer_names +
          " Default format is: '%default'." +
          " Keywords to serializer can be given after format like: %s." %
          kw_example,
          metavar="OUTPUT_FORMAT")
  
      oparser.add_option(
          '--ns',
          action="append", type=str,
          help="Register a namespace binding (QName prefix to a base URI). "
          "This can be used more than once.",
          metavar="PREFIX=NAMESPACE")
  
      oparser.add_option(
          '--no-guess', dest='guess',
          action='store_false', default=True,
          help="Don't guess format based on file suffix.")
  
      oparser.add_option(
          '--no-out',
          action='store_true', default=False,
          help="Don't output the resulting graph " +
               "(useful for checking validity of input).")
  
      oparser.add_option(
          '-w', '--warn',
          action='store_true', default=False,
          help="Output warnings to stderr (by default only critical errors).")
  
      return oparser
  
  _get_plugin_names = lambda kind: ", ".join(
      p.name for p in plugin.plugins(kind=kind))
  
  
  def main():
      oparser = make_option_parser()
      opts, args = oparser.parse_args()
      if len(args) < 1:
          oparser.print_usage()
          oparser.exit()
  
      if opts.warn:
          loglevel = logging.WARNING
      else:
          loglevel = logging.CRITICAL
      logging.basicConfig(level=loglevel)
  
      ns_bindings = {}
      if opts.ns:
          for ns_kw in opts.ns:
              pfx, uri = ns_kw.split('=')
              ns_bindings[pfx] = uri
  
      outfile = sys.stdout
      if PY3:
          outfile = sys.stdout.buffer
  
      if opts.no_out:
          outfile = None
  
      parse_and_serialize(args, opts.input_format, opts.guess,
                          outfile, opts.output_format, ns_bindings)
  
  
  if __name__ == "__main__":
      main()
  