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# Source code for rdflib.tools.rdfpipe

    #!/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 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()

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