made query res pprinter into a serializer

6 files changed, 70 insertions, 64 deletions

diff --git a/docs/plugin_query_results.rst b/docs/plugin_query_results.rst
index 790495b5..2dad7444 100644
--- a/docs/plugin_query_results.rst
+++ b/docs/plugin_query_results.rst
@@ -1,7 +1,7 @@
-.. _plugin_query_results: Plugin Query Results
+.. _plugin_query_results: Plugin query results
 
 ====================
-Plugin Query Results
+Plugin query results
 ====================
 
 Plugins for reading and writing of (SPARQL) :class:`~rdflib.querye.QueryResult` - pass ``name`` to either :meth:`~rdflib.query.QueryResult.parse` or :meth:`~rdflib.query.QueryResult.serialize` 
@@ -27,5 +27,6 @@ Name Class
 ==== ========================================================================
 csv  :class:`~rdflib.plugins.sparql.results.csvresults.CSVResultSerializer`
 json :class:`~rdflib.plugins.sparql.results.jsonresults.JSONResultSerializer`
+txt  :class:`~rdflib.plugins.sparql.results.txtresults.TXTResultSerializer`
 xml  :class:`~rdflib.plugins.sparql.results.xmlresults.XMLResultSerializer`
 ==== ========================================================================
diff --git a/rdflib/plugin.py b/rdflib/plugin.py
index a726f1a9..19ee8eaa 100644
--- a/rdflib/plugin.py
+++ b/rdflib/plugin.py
@@ -285,6 +285,9 @@ register(
     'xml', ResultSerializer,
     'rdflib.plugins.sparql.results.xmlresults', 'XMLResultSerializer')
 register(
+    'txt', ResultSerializer,
+    'rdflib.plugins.sparql.results.txtresults', 'TXTResultSerializer')
+register(
     'json', ResultSerializer,
     'rdflib.plugins.sparql.results.jsonresults', 'JSONResultSerializer')
 register(
diff --git a/rdflib/plugins/sparql/results/txtresults.py b/rdflib/plugins/sparql/results/txtresults.py
new file mode 100644
index 00000000..fd86a784
--- /dev/null
+++ b/rdflib/plugins/sparql/results/txtresults.py
@@ -0,0 +1,60 @@
+
+from rdflib import URIRef, BNode, Literal
+from rdflib.query import ResultSerializer
+
+def _termString(t, namespace_manager):
+    if t == None:
+        return "-"
+    if namespace_manager:
+        if isinstance(t, URIRef): 
+            return namespace_manager.normalizeUri(t)
+        elif isinstance(t, BNode): 
+            return t.n3()
+        elif isinstance(t, Literal): 
+            return t._literal_n3(qname_callback=namespace_manager.normalizeUri)
+    else: 
+        return t.n3()
+
+
+class TXTResultSerializer(ResultSerializer): 
+    """
+    A write only QueryResult serializer for text/ascii tables
+    """
+
+    def serialize(self, stream, encoding, namespace_manager = None): 
+
+        """
+        return a text table of query results
+        """
+
+
+        def c(s, w):
+            """
+            center the string s in w wide string
+            """
+            w -= len(s)
+            h1 = h2 = w // 2
+            if w % 2: h2 += 1
+            return " " * h1 + s + " " * h2
+
+        if self.result.type!='SELECT': 
+            raise Exception("Can only pretty print SELECT results!")
+
+        if not self.result:
+            return "(no results)\n"
+        else:
+
+            keys = sorted(self.result.vars)
+            maxlen = [0] * len(keys)
+            b = [[_termString(r[k], namespace_manager) for k in keys] for r in self.result]
+            for r in b:
+                for i in range(len(keys)):
+                    maxlen[i] = max(maxlen[i], len(r[i]))
+
+            stream.write(
+                "|".join([c(k, maxlen[i]) for i, k in enumerate(keys)]) + "\n")
+            stream.write("-" * (len(maxlen)+sum(maxlen)) + "\n")
+            for r in sorted(b):
+                stream.write("|".join(
+                    [t + " " * (i - len(t)) for i, t in zip(maxlen, r)]) + "\n")
+
diff --git a/rdflib/query.py b/rdflib/query.py
index 0092603a..1bed4e98 100644
--- a/rdflib/query.py
+++ b/rdflib/query.py
@@ -295,7 +295,7 @@ class ResultParser(object):
     def __init__(self):
         pass
 
-    def parse(self, source):
+    def parse(self, source, **kwargs):
         """return a Result object"""
         pass  # abstract
 
@@ -305,6 +305,6 @@ class ResultSerializer(object):
     def __init__(self, result):
         self.result = result
 
-    def serialize(self, stream, encoding="utf-8"):
+    def serialize(self, stream, encoding="utf-8", **kwargs):
         """return a string properly serialized"""
         pass  # abstract
diff --git a/rdflib/util.py b/rdflib/util.py
index 305c4dc1..32bb8da9 100644
--- a/rdflib/util.py
+++ b/rdflib/util.py
@@ -464,62 +464,6 @@ def get_tree(graph,
     return (mapper(root), sorted(tree, key=sortkey))
 
 
-def pprint_query_results(res, namespace_manager = None, stream = None):
-
-    """
-    return a text table of query results
-    """
-
-    def termString(t):
-        if t == None:
-            return "-"
-        if namespace_manager:
-            if isinstance(t, URIRef): 
-                return namespace_manager.normalizeUri(t)
-            elif isinstance(t, BNode): 
-                return t.n3()
-            elif isinstance(t, Literal): 
-                return t._literal_n3(qname_callback=namespace_manager.normalizeUri)
-        else: 
-            return t.n3()
-
-    def c(s, w):
-        """
-        center the string s in w wide string
-        """
-        h = (w - len(s)) // 2
-        return " " * h + s + " " * h
-
-    if res.type!='SELECT': 
-        raise Exception("Can only pretty print SELECT results!")
-
-    if not res:
-        return "(no results)\n"
-    else:
-        if stream: 
-            out = stream
-        else: 
-            out = StringIO()
-        # keys = r.vars
-        # for r in b:
-        #     keys.update(r.keys())
-
-        keys = sorted(res.vars)
-        maxlen = [0] * len(keys)
-        b = [[termString(r[k]) for k in keys] for r in res]
-        for r in b:
-            for i in range(len(keys)):
-                maxlen[i] = max(maxlen[i], 1 + len(r[i]))
-
-        out.write(
-            "|".join([c(k, maxlen[i]) for i, k in enumerate(keys)]) + "\n")
-        out.write("-" * sum(maxlen) + "\n")
-        for r in sorted(b):
-            out.write("|".join(
-                [t + " " * (i - len(t) - 1) for i, t in zip(maxlen, r)]) + "\n")
-
-        if not stream: 
-            return out.getvalue()
 
 
 def test():
diff --git a/test/test_dawg.py b/test/test_dawg.py
index d7ea1a71..e4aacb67 100644
--- a/test/test_dawg.py
+++ b/test/test_dawg.py
@@ -43,8 +43,6 @@ from rdflib.plugins.sparql.update import evalUpdate
 
 from rdflib.py3compat import decodeStringEscape
 
-from rdflib.util import pprint_query_results
-
 from nose.tools import nottest, eq_ as eq
 from nose import SkipTest
 
@@ -440,8 +438,8 @@ def query_test(t):
                     set(res),
                     set(res2)
                 ), 'Bindings do not match: \n%s\n!=\n%s' % (
-                    pprint_query_results(res, namespace_manager=g.namespace_manager),
-                    pprint_query_results(res2, namespace_manager=g.namespace_manager))
+                    res.serialize(format='txt', namespace_manager=g.namespace_manager),
+                    res2.serialize(format='txt', namespace_manager=g.namespace_manager))
             elif res.type == 'ASK':
                 eq(res.askAnswer,
                    res2.askAnswer, "Ask answer does not match: %r != %r" % (