add 'contributions summarize' command

Change-Id: Ib6aca3be27fbc99a6be9ecb735659869726c5e5e
Signed-off-by: Doug Hellmann <doug@doughellmann.com>

goal_tools/tests/test_summarize.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.
+
+import collections
+
+from goal_tools.who_helped import summarize
+from goal_tools.tests import base
+
+
+class TestSummarizeBy(base.TestCase):
+
+    _data = [
+        {'a': 'A', 'b': 'B'},
+        {'a': 'A', 'b': 'C'},
+    ]
+
+    def test_one_column(self):
+        results = summarize._summarize_by(['a'], self._data)
+        expected = collections.Counter({('A',): 2})
+        self.assertEqual(expected, results)
+
+    def test_two_columns(self):
+        results = summarize._summarize_by(['a', 'b'], self._data)
+        expected = collections.Counter({
+            ('A', 'B'): 1,
+            ('A', 'C'): 1,
+        })
+        self.assertEqual(expected, results)

goal_tools/who_helped/summarize.py

@@ -0,0 +1,63 @@
+# 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 collections
+import csv
+import logging
+
+from cliff import lister
+
+LOG = logging.getLogger(__name__)
+
+
+def _summarize_by(by_names, data_source):
+    counts = collections.Counter()
+    counts.update(
+        tuple(row[by] for by in by_names)
+        for row in data_source
+    )
+    return counts
+
+
+class SummarizeContributions(lister.Lister):
+    "Summarize a contribution report."
+
+    def get_parser(self, prog_name):
+        parser = super().get_parser(prog_name)
+        parser.add_argument(
+            '--by', '-b',
+            action='append',
+            default=[],
+            help='columns to summarize by',
+        )
+        parser.add_argument(
+            'contribution_list',
+            nargs='+',
+            help='name(s) of files containing contribution details',
+        )
+        return parser
+
+    def take_action(self, parsed_args):
+        if not parsed_args.by:
+            raise RuntimeError('No --by values specified')
+
+        def rows():
+            for filename in parsed_args.contribution_list:
+                LOG.debug('reading %s', filename)
+                with open(filename, 'r', encoding='utf-8') as f:
+                    reader = csv.DictReader(f)
+                    yield from reader
+
+        counts = _summarize_by(parsed_args.by, rows())
+        items = reversed(sorted(counts.items(), key=lambda x: x[1]))
+        columns = tuple(parsed_args.by) + ('Count',)
+        return (columns, (cols + (count,) for cols, count in items))

setup.cfg

@@ -30,6 +30,7 @@ console_scripts =
 
 who_helped =
     contributions list = goal_tools.who_helped.contributions:ListContributions
+    contributions summarize = goal_tools.who_helped.summarize:SummarizeContributions
     member show = goal_tools.who_helped.members:ShowMember
 	changes query = goal_tools.who_helped.changes:QueryChanges
 	cache remove = goal_tools.who_helped.cache:CacheRemove