[Findit] Add iterator and crash_iterator for delta test

appengine/findit/util_scripts/crash_queries/crash_printer/print_crash.py

+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import argparse
+from datetime import date
+from datetime import timedelta
+
+from crash_queries.crash_printer import crash_printer
+
+_TODAY = date.today().strftime('%Y-%m-%d')
+_A_YEAR_AGO = (date.today() - timedelta(days=365)).strftime('%Y-%m-%d')
+
+
+if __name__ == '__main__':
+  argparser = argparse.ArgumentParser(
+      description='Print crashes.')
+
+  argparser.add_argument(
+      '--date',
+      '-d',
+      default='%s..%s' % (_A_YEAR_AGO, _TODAY),
+      help=('Should be in start_date..end_date format.'

[stgao, 2016/10/10 23:39:40]

Maybe give a real example too.

[Sharu Jiang, 2016/10/12 00:52:11]

Done.

+            'If the end date is missing, then it defaults to today. '
+            'If the start date is missing, then it defaults to a year before '
+            'the end date.'
+            'Start date and end date to query data in [start_date, end_date)'))
+
+  argparser.add_argument(
+      '--client',
+      '-c',
+      default='fracas',
+      help=('Possible values are: fracas, cracas, clusterfuzz. Right now, only '
+            'fracas is supported.'))
+
+  args = argparser.parse_args()
+
+  start_date, end_date = args.date.split('..')
+  if not start_date:
+    start_date = _A_YEAR_AGO

[stgao, 2016/10/10 23:39:40]

If the end date is provided, this doesn't conform to the description in #25.

[Sharu Jiang, 2016/10/12 00:52:11]

Done.

+  if not end_date:
+    end_date = _TODAY
+
+  crash_printer.CrashPrinter(args.client,
+                             start_date=start_date, end_date=end_date)