[Findit] Add iterator and crash_iterator for delta test

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

Index: appengine/findit/util_scripts/crash_queries/crash_printer/print_crash.py
diff --git a/appengine/findit/util_scripts/crash_queries/crash_printer/print_crash.py b/appengine/findit/util_scripts/crash_queries/crash_printer/print_crash.py
new file mode 100644
index 0000000000000000000000000000000000000000..e0801fa8146af9e766e16d09c1ce7f15c7c260cb
--- /dev/null
+++ b/appengine/findit/util_scripts/crash_queries/crash_printer/print_crash.py
@@ -0,0 +1,48 @@
+# 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
+import os
+
+from crash_queries.crash_printer import crash_printer
+
+_DATETIME_FORMAT = '%Y-%m-%d'
+_TODAY = date.today().strftime(_DATETIME_FORMAT)
+_A_YEAR_AGO = (date.today() - timedelta(days=365)).strftime(_DATETIME_FORMAT)
+
+
+if __name__ == '__main__':
+  argparser = argparse.ArgumentParser(
+      description='Print crashes.')
+
+  argparser.add_argument(
+      '--since',
+      '--after',

[stgao, 2016/10/14 00:55:01]

Why we have two names here?

[Sharu Jiang, 2016/10/14 18:14:49]

This is similar to args of git log command:  
https://git-scm.com/docs/git-log

Just give people more options to remember.

[stgao, 2016/10/19 00:49:47]

I rarely see such a usage.

What's the consideration behind that? Why people want two options? Does it
really help out?

[Sharu Jiang, 2016/10/19 20:12:44]

Maybe when people can not remember clearly whether parameters are (since, until)
or (after, before), they can use either of the cases.

I am ok either way(2 options or 1), if you think 1 name is better, I can remove
the (after, before) names.

[stgao, 2016/10/20 01:18:37]

When people don't remember, they should run "script.py -h".
That's the common usage.

[Sharu Jiang, 2016/10/20 20:38:21]

Acknowledged.

[wrengr, 2016/10/24 18:09:37]

FWIW, I agree with stgao here. Having multiple ways to spell a flag/argument is
generally a bad idea. For standard *nix tools, the only time they have redundant
flags is for legacy reasons, and they typically mark one set as being
deprecated. Since we have no such legacy to support, we should keep it clean.
Git has both a terrible UI, and one that isn't mirrored by the rest of the
ecosystem; there's no reason to try to emulate it. Just have a -h, --help,
and/or -? flag which people can query if they forget.

+      default=_A_YEAR_AGO,
+      help=('Query data since this date (including this date). '
+            'Should be in YYYY-MM-DD format. E.g. 2015-09-31. '
+            'Defaults to a year ago.'))
+
+  argparser.add_argument(
+      '--until',
+      '--before',

[stgao, 2016/10/14 00:55:01]

same here.

[Sharu Jiang, 2016/10/14 18:14:49]

Ditto.

+      default=_TODAY,
+      help=('Query data until this date (not including this date). '
+            'Should be in YYYY-MM-DD format. E.g. 2015-09-31. '
+            'Defaults to today.'))
+
+  argparser.add_argument(
+      '--client',
+      '-c',
+      default='fracas',
+      help=('Possible values are: fracas, cracas, clusterfuzz. Right now, only '
+            'fracas is supported.'))
+
+  args = argparser.parse_args()
+
+  crash_printer.CrashPrinter(args.client,
+                             start_date=args.since, end_date=args.until,
+                             app_id=os.getenv('APP_ID'))