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comparison planemo/lib/python3.7/site-packages/rdflib/plugins/serializers/nt.py @ 1:56ad4e20f292 draft

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"planemo upload commit 6eee67778febed82ddd413c3ca40b3183a3898f1"
author guerler
date Fri, 31 Jul 2020 00:32:28 -0400
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0:d30785e31577 1:56ad4e20f292
1 """
2 N-Triples RDF graph serializer for RDFLib.
3 See <http://www.w3.org/TR/rdf-testcases/#ntriples> for details about the
4 format.
5 """
6 from rdflib.term import Literal
7 from rdflib.serializer import Serializer
8 from rdflib.py3compat import b
9
10 import warnings
11 import codecs
12
13 __all__ = ['NTSerializer']
14
15
16 class NTSerializer(Serializer):
17 """
18 Serializes RDF graphs to NTriples format.
19 """
20
21 def __init__(self, store):
22 Serializer.__init__(self, store)
23 self.encoding = 'ascii' # n-triples are ascii encoded
24
25 def serialize(self, stream, base=None, encoding=None, **args):
26 if base is not None:
27 warnings.warn("NTSerializer does not support base.")
28 if encoding is not None:
29 warnings.warn("NTSerializer does not use custom encoding.")
30 encoding = self.encoding
31 for triple in self.store:
32 stream.write(_nt_row(triple).encode(self.encoding, "_rdflib_nt_escape"))
33 stream.write(b("\n"))
34
35
36 class NT11Serializer(NTSerializer):
37 """
38 Serializes RDF graphs to RDF 1.1 NTriples format.
39
40 Exactly like nt - only utf8 encoded.
41 """
42
43 def __init__(self, store):
44 Serializer.__init__(self, store) # default to utf-8
45
46
47 def _nt_row(triple):
48 if isinstance(triple[2], Literal):
49 return "%s %s %s .\n" % (
50 triple[0].n3(),
51 triple[1].n3(),
52 _quoteLiteral(triple[2]))
53 else:
54 return "%s %s %s .\n" % (triple[0].n3(),
55 triple[1].n3(),
56 triple[2].n3())
57
58
59 def _quoteLiteral(l):
60 '''
61 a simpler version of term.Literal.n3()
62 '''
63
64 encoded = _quote_encode(l)
65
66 if l.language:
67 if l.datatype:
68 raise Exception("Literal has datatype AND language!")
69 return '%s@%s' % (encoded, l.language)
70 elif l.datatype:
71 return '%s^^<%s>' % (encoded, l.datatype)
72 else:
73 return '%s' % encoded
74
75
76 def _quote_encode(l):
77 return '"%s"' % l.replace('\\', '\\\\')\
78 .replace('\n', '\\n')\
79 .replace('"', '\\"')\
80 .replace('\r', '\\r')
81
82 def _nt_unicode_error_resolver(err):
83
84 """
85 Do unicode char replaces as defined in https://www.w3.org/TR/2004/REC-rdf-testcases-20040210/#ntrip_strings
86 """
87
88 def _replace_single(c):
89 c = ord(c)
90 fmt = '\\u%04X' if c <= 0xFFFF else '\\U%08X'
91 return fmt % c
92
93 string = err.object[err.start:err.end]
94 return ( "".join( _replace_single(c) for c in string ), err.end )
95
96 codecs.register_error('_rdflib_nt_escape', _nt_unicode_error_resolver)