add 'contributions distinct' command

Add a tool to find sets of distinct values within a data set.

Change-Id: I193ef507e3e3a688508c2902673cb9327f4e528c
Signed-off-by: Doug Hellmann <doug@doughellmann.com>

goal_tools/tests/test_distinct.py

@@ -0,0 +1,37 @@
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+from goal_tools.who_helped import distinct
+from goal_tools.tests import base
+
+
+class TestGetDistinct(base.TestCase):
+
+    _data = [
+        {'a': 'A', 'b': 'B', 'c': 'C', 'd': 'D'},
+        {'a': 'A', 'b': 'C', 'c': 'D', 'd': 'D'},
+    ]
+
+    def test_group_by_one_column(self):
+        results = distinct._get_distinct(['a'], self._data)
+        expected = set([
+            ('A',),
+        ])
+        self.assertEqual(expected, results)
+
+    def test_group_by_two_columns(self):
+        results = distinct._get_distinct(['a', 'b'], self._data)
+        expected = set([
+            ('A', 'B'),
+            ('A', 'C'),
+        ])
+        self.assertEqual(expected, results)

goal_tools/who_helped/distinct.py

@@ -0,0 +1,56 @@
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import logging
+
+from goal_tools.who_helped import contributions
+from goal_tools.who_helped import report
+
+LOG = logging.getLogger(__name__)
+
+
+def _get_distinct(by_names, data_source):
+    return set(
+        tuple(row[b] for b in by_names)
+        for row in data_source
+    )
+
+
+class DistinctContributions(report.ContributionsReportBase):
+    "Show distinct values in a contribution report."
+
+    def get_parser(self, prog_name):
+        parser = super().get_parser(prog_name)
+        parser.add_argument(
+            '--by', '-b',
+            action='append',
+            default=[],
+            choices=contributions._COLUMNS,
+            help=('column(s) to summarize by (may be repeated), '
+                  'defaults to "Organization"'),
+        )
+        return parser
+
+    def take_action(self, parsed_args):
+        group_by = parsed_args.by[:]
+        if not group_by:
+            group_by.append('Organization')
+
+        data = self.get_contributions(parsed_args)
+
+        values = _get_distinct(group_by, data)
+
+        output_rows = sorted(values)
+
+        columns = tuple(group_by)
+
+        return (columns, output_rows)

setup.cfg

@@ -31,6 +31,7 @@ console_scripts =
 who_helped =
     contributions list = goal_tools.who_helped.contributions:ListContributions
     contributions summarize = goal_tools.who_helped.summarize:SummarizeContributions
+    contributions distinct = goal_tools.who_helped.distinct:DistinctContributions
     member show = goal_tools.who_helped.members:ShowMember
 	changes query = goal_tools.who_helped.changes:QueryChanges
 	cache remove = goal_tools.who_helped.cache:CacheRemove