#!/usr/bin/env python
"""
A commandline tool for parsing RDF in different formats and serializing the
resulting graph to a chosen format.
"""
from __future__ import annotations
import logging
import sys
from optparse import OptionParser
from typing import BinaryIO, Optional
import rdflib
from rdflib import plugin
from rdflib.graph import ConjunctiveGraph
from rdflib.parser import Parser
from rdflib.serializer import Serializer
from rdflib.store import Store
from rdflib.util import guess_format
DEFAULT_INPUT_FORMAT = "xml"
DEFAULT_OUTPUT_FORMAT = "n3"
[docs]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
[docs]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
def _get_plugin_names(kind):
return ", ".join(p.name for p in plugin.plugins(kind=kind))
[docs]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: Optional[BinaryIO] = 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()
