Add better date / datetime validation (pull 2)

addition to #631 with update to master + timefield support

docs/api-guide/fields.md

@@ -185,12 +185,20 @@ Corresponds to `django.forms.fields.RegexField`
 
 A date representation.
 
+Uses `DATE_INPUT_FORMATS` to validate date.
+
+Optionally takes `format` as parameter to replace the matching pattern.
+
 Corresponds to `django.db.models.fields.DateField`
 
 ## DateTimeField
 
 A date and time representation.
 
+Uses `DATETIME_INPUT_FORMATS` to validate date_time.
+
+Optionally takes `format` as parameter to replace the matching pattern.
+
 Corresponds to `django.db.models.fields.DateTimeField`
 
 When using `ModelSerializer` or `HyperlinkedModelSerializer`, note that any model fields with `auto_now=True` or `auto_now_add=True` will use serializer fields that are `read_only=True` by default.
@@ -207,6 +215,10 @@ If you want to override this behavior, you'll need to declare the `DateTimeField
 
 A time representation.
 
+Uses `TIME_INPUT_FORMATS` to validate time.
+
+Optionally takes `format` as parameter to replace the matching pattern.
+
 Corresponds to `django.db.models.fields.TimeField`
 
 ## IntegerField

docs/topics/release-notes.md

@@ -44,6 +44,9 @@ You can determine your currently installed version using `pip freeze`:
 
 * Bugfix for serializer data being uncacheable with pickle protocol 0.
 * Bugfixes for model field validation edge-cases.
+* Support `DATE_INPUT_FORMATS` for `DateField` validation
+* Support `DATETIME_INPUT_FORMATS` for `DateTimeField` validation
+* Support `TIME_INPUT_FORMATS` for `TimeField` validation
 
 ### 2.2.1
 

rest_framework/fields.py

@@ -19,6 +19,7 @@ from rest_framework.compat import BytesIO
 from rest_framework.compat import six
 from rest_framework.compat import smart_text
 from rest_framework.compat import parse_time
+from rest_framework.utils.dates import get_readable_date_format
 
 
 def is_simple_callable(obj):
@@ -447,13 +448,14 @@ class DateField(WritableField):
     form_field_class = forms.DateField
 
     default_error_messages = {
-        'invalid': _("'%s' value has an invalid date format. It must be "
+        'invalid': _(u"Date has wrong format. Use one of these formats instead: %s"),
-                     "in YYYY-MM-DD format."),
-        'invalid_date': _("'%s' value has the correct format (YYYY-MM-DD) "
-                          "but it is an invalid date."),
     }
     empty = None
 
+    def __init__(self, *args, **kwargs):
+        self.format = kwargs.pop('format', settings.DATE_INPUT_FORMATS)
+        super(DateField, self).__init__(*args, **kwargs)
+
     def from_native(self, value):
         if value in validators.EMPTY_VALUES:
             return None
@@ -468,15 +470,16 @@ class DateField(WritableField):
         if isinstance(value, datetime.date):
             return value
 
+        for format in self.format:
             try:
-            parsed = parse_date(value)
+                parsed = datetime.datetime.strptime(value, format)
-            if parsed is not None:
-                return parsed
             except (ValueError, TypeError):
-            msg = self.error_messages['invalid_date'] % value
+                pass
-            raise ValidationError(msg)
+            else:
+                return parsed.date()
 
-        msg = self.error_messages['invalid'] % value
+        date_input_formats = '; '.join(self.format)
+        msg = self.error_messages['invalid'] % get_readable_date_format(date_input_formats)
         raise ValidationError(msg)
 
 
@@ -486,16 +489,14 @@ class DateTimeField(WritableField):
     form_field_class = forms.DateTimeField
 
     default_error_messages = {
-        'invalid': _("'%s' value has an invalid format. It must be in "
+        'invalid': _(u"Datetime has wrong format. Use one of these formats instead: %s"),
-                     "YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ] format."),
-        'invalid_date': _("'%s' value has the correct format "
-                          "(YYYY-MM-DD) but it is an invalid date."),
-        'invalid_datetime': _("'%s' value has the correct format "
-                              "(YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ]) "
-                              "but it is an invalid date/time."),
     }
     empty = None
 
+    def __init__(self, *args, **kwargs):
+        self.format = kwargs.pop('format', settings.DATETIME_INPUT_FORMATS)
+        super(DateTimeField, self).__init__(*args, **kwargs)
+
     def from_native(self, value):
         if value in validators.EMPTY_VALUES:
             return None
@@ -516,23 +517,16 @@ class DateTimeField(WritableField):
                 value = timezone.make_aware(value, default_timezone)
             return value
 
+        for format in self.format:
             try:
-            parsed = parse_datetime(value)
+                parsed = datetime.datetime.strptime(value, format)
-            if parsed is not None:
+            except (ValueError, TypeError):
+                pass
+            else:
                 return parsed
-        except (ValueError, TypeError):
-            msg = self.error_messages['invalid_datetime'] % value
-            raise ValidationError(msg)
 
-        try:
+        datetime_input_formats = '; '.join(self.format)
-            parsed = parse_date(value)
+        msg = self.error_messages['invalid'] % get_readable_date_format(datetime_input_formats)
-            if parsed is not None:
-                return datetime.datetime(parsed.year, parsed.month, parsed.day)
-        except (ValueError, TypeError):
-            msg = self.error_messages['invalid_date'] % value
-            raise ValidationError(msg)
-
-        msg = self.error_messages['invalid'] % value
         raise ValidationError(msg)
 
 
@@ -542,11 +536,14 @@ class TimeField(WritableField):
     form_field_class = forms.TimeField
 
     default_error_messages = {
-        'invalid': _("'%s' value has an invalid format. It must be a valid "
+        'invalid': _(u"Time has wrong format. Use one of these formats instead: %s"),
-                     "time in the HH:MM[:ss[.uuuuuu]] format."),
     }
     empty = None
 
+    def __init__(self, *args, **kwargs):
+        self.format = kwargs.pop('format', settings.TIME_INPUT_FORMATS)
+        super(TimeField, self).__init__(*args, **kwargs)
+
     def from_native(self, value):
         if value in validators.EMPTY_VALUES:
             return None
@@ -554,12 +551,16 @@ class TimeField(WritableField):
         if isinstance(value, datetime.time):
             return value
 
+        for format in self.format:
             try:
-            parsed = parse_time(value)
+                parsed = datetime.datetime.strptime(value, format)
-            assert parsed is not None
-            return parsed
             except (ValueError, TypeError):
-            msg = self.error_messages['invalid'] % value
+                pass
+            else:
+                return parsed.time()
+
+        time_input_formats = '; '.join(self.format)
+        msg = self.error_messages['invalid'] % get_readable_date_format(time_input_formats)
         raise ValidationError(msg)
 
 

rest_framework/tests/fields.py

@@ -3,9 +3,13 @@ General serializer field tests.
 """
 from __future__ import unicode_literals
 import datetime
+
+import django
 from django.db import models
 from django.test import TestCase
 from django.core import validators
+from django.utils import unittest
+
 from rest_framework import serializers
 
 
@@ -18,6 +22,21 @@ class CharPrimaryKeyModel(models.Model):
     id = models.CharField(max_length=20, primary_key=True)
 
 
+class DateObject(object):
+    def __init__(self, date):
+        self.date = date
+
+
+class DateTimeObject(object):
+    def __init__(self, date_time):
+        self.date_time = date_time
+
+
+class TimeObject(object):
+    def __init__(self, time):
+        self.time = time
+
+
 class TimestampedModelSerializer(serializers.ModelSerializer):
     class Meta:
         model = TimestampedModel
@@ -28,6 +47,66 @@ class CharPrimaryKeyModelSerializer(serializers.ModelSerializer):
         model = CharPrimaryKeyModel
 
 
+class DateObjectSerializer(serializers.Serializer):
+    date = serializers.DateField()
+
+    def restore_object(self, attrs, instance=None):
+        if instance is not None:
+            instance.date = attrs['date']
+            return instance
+        return DateObject(**attrs)
+
+
+class DateObjectCustomFormatSerializer(serializers.Serializer):
+    date = serializers.DateField(format=("%Y", "%Y -- %m"))
+
+    def restore_object(self, attrs, instance=None):
+        if instance is not None:
+            instance.date = attrs['date']
+            return instance
+        return DateObject(**attrs)
+
+
+class DateTimeObjectSerializer(serializers.Serializer):
+    date_time = serializers.DateTimeField()
+
+    def restore_object(self, attrs, instance=None):
+        if instance is not None:
+            instance.date_time = attrs['date_time']
+            return instance
+        return DateTimeObject(**attrs)
+
+
+class DateTimeObjectCustomFormatSerializer(serializers.Serializer):
+    date_time = serializers.DateTimeField(format=("%Y", "%Y %H:%M"))
+
+    def restore_object(self, attrs, instance=None):
+        if instance is not None:
+            instance.date_time = attrs['date_time']
+            return instance
+        return DateTimeObject(**attrs)
+
+
+class TimeObjectSerializer(serializers.Serializer):
+    time = serializers.TimeField()
+
+    def restore_object(self, attrs, instance=None):
+        if instance is not None:
+            instance.time = attrs['time']
+            return instance
+        return TimeObject(**attrs)
+
+
+class TimeObjectCustomFormatSerializer(serializers.Serializer):
+    time = serializers.TimeField(format=("%H -- %M", "%H%M%S"))
+
+    def restore_object(self, attrs, instance=None):
+        if instance is not None:
+            instance.time = attrs['time']
+            return instance
+        return TimeObject(**attrs)
+
+
 class TimeFieldModel(models.Model):
     clock = models.TimeField()
 
@@ -59,37 +138,275 @@ class BasicFieldTests(TestCase):
         serializer = CharPrimaryKeyModelSerializer()
         self.assertEquals(serializer.fields['id'].read_only, False)
 
-    def test_TimeField_from_native(self):
+
+class DateFieldTest(TestCase):
+    def test_valid_default_date_input_formats(self):
+        serializer = DateObjectSerializer(data={'date': '1984-07-31'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateObjectSerializer(data={'date': '07/31/1984'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateObjectSerializer(data={'date': '07/31/84'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateObjectSerializer(data={'date': 'Jul 31 1984'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateObjectSerializer(data={'date': 'Jul 31, 1984'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateObjectSerializer(data={'date': '31 Jul 1984'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateObjectSerializer(data={'date': '31 Jul 1984'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateObjectSerializer(data={'date': 'July 31 1984'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateObjectSerializer(data={'date': 'July 31, 1984'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateObjectSerializer(data={'date': '31 July 1984'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateObjectSerializer(data={'date': '31 July, 1984'})
+        self.assertTrue(serializer.is_valid())
+
+    def test_valid_custom_date_input_formats(self):
+        serializer = DateObjectCustomFormatSerializer(data={'date': '1984'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateObjectCustomFormatSerializer(data={'date': '1984 -- 07'})
+        self.assertTrue(serializer.is_valid())
+
+    def test_wrong_default_date_input_format(self):
+        serializer = DateObjectSerializer(data={'date': 'something wrong'})
+        self.assertFalse(serializer.is_valid())
+        self.assertEquals(serializer.errors, {'date': [u'Date has wrong format. Use one of these formats instead: '
+                                                       u'YYYY-MM-DD; MM/DD/YYYY; MM/DD/YY; [Jan through Dec] DD YYYY; '
+                                                       u'[Jan through Dec] DD, YYYY; DD [Jan through Dec] YYYY; '
+                                                       u'DD [Jan through Dec], YYYY; [January through December] DD YYYY; '
+                                                       u'[January through December] DD, YYYY; DD [January through December] YYYY; '
+                                                       u'DD [January through December], YYYY']})
+
+    def test_wrong_custom_date_input_format(self):
+        serializer = DateObjectCustomFormatSerializer(data={'date': '07/31/1984'})
+        self.assertFalse(serializer.is_valid())
+        self.assertEquals(serializer.errors, {'date': [u'Date has wrong format. Use one of these formats instead: YYYY; YYYY -- MM']})
+
+    def test_from_native(self):
+        f = serializers.DateField()
+        result = f.from_native('1984-07-31')
+
+        self.assertEqual(datetime.date(1984, 7, 31), result)
+
+    def test_from_native_datetime_date(self):
+        """
+        Make sure from_native() accepts a datetime.date instance.
+        """
+        f = serializers.DateField()
+        result = f.from_native(datetime.date(1984, 7, 31))
+
+        self.assertEqual(result, datetime.date(1984, 7, 31))
+
+    def test_from_native_empty(self):
+        f = serializers.DateField()
+        result = f.from_native('')
+
+        self.assertEqual(result, None)
+
+    def test_from_native_invalid_date(self):
+        f = serializers.DateField()
+
+        try:
+            f.from_native('1984-42-31')
+        except validators.ValidationError as e:
+            self.assertEqual(e.messages, [u'Date has wrong format. Use one of these formats instead: '
+                                          u'YYYY-MM-DD; MM/DD/YYYY; MM/DD/YY; [Jan through Dec] DD YYYY; '
+                                          u'[Jan through Dec] DD, YYYY; DD [Jan through Dec] YYYY; '
+                                          u'DD [Jan through Dec], YYYY; [January through December] DD YYYY; '
+                                          u'[January through December] DD, YYYY; DD [January through December] YYYY; '
+                                          u'DD [January through December], YYYY'])
+        else:
+            self.fail("ValidationError was not properly raised")
+
+
+class DateTimeFieldTest(TestCase):
+    def test_valid_default_date_time_input_formats(self):
+        serializer = DateTimeObjectSerializer(data={'date_time': '1984-07-31 04:31:59'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateTimeObjectSerializer(data={'date_time': '1984-07-31 04:31'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateTimeObjectSerializer(data={'date_time': '1984-07-31'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateTimeObjectSerializer(data={'date_time': '07/31/1984 04:31:59'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateTimeObjectSerializer(data={'date_time': '07/31/1984 04:31'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateTimeObjectSerializer(data={'date_time': '07/31/1984'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateTimeObjectSerializer(data={'date_time': '07/31/84 04:31:59'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateTimeObjectSerializer(data={'date_time': '07/31/84 04:31'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateTimeObjectSerializer(data={'date_time': '07/31/84'})
+        self.assertTrue(serializer.is_valid())
+
+    @unittest.skipUnless(django.VERSION >= (1, 4), "django < 1.4 don't have microseconds in default settings")
+    def test_valid_default_date_time_input_formats_for_django_gte_1_4(self):
+        serializer = DateTimeObjectSerializer(data={'date_time': '1984-07-31 04:31:59.123456'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateTimeObjectSerializer(data={'date_time': '07/31/1984 04:31:59.123456'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateTimeObjectSerializer(data={'date_time': '07/31/84 04:31:59.123456'})
+        self.assertTrue(serializer.is_valid())
+
+    def test_valid_custom_date_time_input_formats(self):
+        serializer = DateTimeObjectCustomFormatSerializer(data={'date_time': '1984'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = DateTimeObjectCustomFormatSerializer(data={'date_time': '1984 04:31'})
+        self.assertTrue(serializer.is_valid())
+
+    @unittest.skipUnless(django.VERSION >= (1, 4), "django < 1.4 don't have microseconds in default settings")
+    def test_wrong_default_date_time_input_format_for_django_gte_1_4(self):
+        serializer = DateTimeObjectSerializer(data={'date_time': 'something wrong'})
+        self.assertFalse(serializer.is_valid())
+        self.assertEquals(serializer.errors, {'date_time': [u'Datetime has wrong format. Use one of these formats instead: '
+                                                            u'YYYY-MM-DD HH:MM:SS; YYYY-MM-DD HH:MM:SS.uuuuuu; YYYY-MM-DD HH:MM; '
+                                                            u'YYYY-MM-DD; MM/DD/YYYY HH:MM:SS; MM/DD/YYYY HH:MM:SS.uuuuuu; '
+                                                            u'MM/DD/YYYY HH:MM; MM/DD/YYYY; MM/DD/YY HH:MM:SS; '
+                                                            u'MM/DD/YY HH:MM:SS.uuuuuu; MM/DD/YY HH:MM; MM/DD/YY']})
+
+    @unittest.skipUnless(django.VERSION < (1, 4), "django >= 1.4 have microseconds in default settings")
+    def test_wrong_default_date_time_input_format_for_django_lt_1_4(self):
+        serializer = DateTimeObjectSerializer(data={'date_time': 'something wrong'})
+        self.assertFalse(serializer.is_valid())
+        self.assertEquals(serializer.errors, {'date_time': [u'Datetime has wrong format. Use one of these formats instead:'
+                                                            u' YYYY-MM-DD HH:MM:SS; YYYY-MM-DD HH:MM; YYYY-MM-DD; '
+                                                            u'MM/DD/YYYY HH:MM:SS; MM/DD/YYYY HH:MM; MM/DD/YYYY; '
+                                                            u'MM/DD/YY HH:MM:SS; MM/DD/YY HH:MM; MM/DD/YY']})
+
+    def test_wrong_custom_date_time_input_format(self):
+        serializer = DateTimeObjectCustomFormatSerializer(data={'date_time': '07/31/84 04:31'})
+        self.assertFalse(serializer.is_valid())
+        self.assertEquals(serializer.errors, {'date_time': [u'Datetime has wrong format. Use one of these formats instead: YYYY; YYYY HH:MM']})
+
+    def test_from_native(self):
+        f = serializers.DateTimeField()
+        result = f.from_native('1984-07-31 04:31')
+
+        self.assertEqual(datetime.datetime(1984, 7, 31, 4, 31), result)
+
+    def test_from_native_datetime_datetime(self):
+        """
+        Make sure from_native() accepts a datetime.date instance.
+        """
+        f = serializers.DateTimeField()
+        result = f.from_native(datetime.datetime(1984, 7, 31))
+
+        self.assertEqual(result, datetime.datetime(1984, 7, 31))
+
+    def test_from_native_empty(self):
+        f = serializers.DateTimeField()
+        result = f.from_native('')
+
+        self.assertEqual(result, None)
+
+    @unittest.skipUnless(django.VERSION >= (1, 4), "django < 1.4 don't have microseconds in default settings")
+    def test_from_native_invalid_datetime(self):
+        f = serializers.DateTimeField()
+
+        try:
+            f.from_native('1984-42-31 04:31')
+        except validators.ValidationError as e:
+            self.assertEqual(e.messages, [u'Datetime has wrong format. Use one of these formats instead: '
+                                          u'YYYY-MM-DD HH:MM:SS; YYYY-MM-DD HH:MM:SS.uuuuuu; YYYY-MM-DD HH:MM; '
+                                          u'YYYY-MM-DD; MM/DD/YYYY HH:MM:SS; MM/DD/YYYY HH:MM:SS.uuuuuu; '
+                                          u'MM/DD/YYYY HH:MM; MM/DD/YYYY; MM/DD/YY HH:MM:SS; '
+                                          u'MM/DD/YY HH:MM:SS.uuuuuu; MM/DD/YY HH:MM; MM/DD/YY'])
+        else:
+            self.fail("ValidationError was not properly raised")
+
+    @unittest.skipUnless(django.VERSION < (1, 4), "django >= 1.4 have microseconds in default settings")
+    def test_from_native_invalid_datetime(self):
+        f = serializers.DateTimeField()
+
+        try:
+            f.from_native('1984-42-31 04:31')
+        except validators.ValidationError as e:
+            self.assertEqual(e.messages, [u'Datetime has wrong format. Use one of these formats instead:'
+                                          u' YYYY-MM-DD HH:MM:SS; YYYY-MM-DD HH:MM; YYYY-MM-DD; '
+                                          u'MM/DD/YYYY HH:MM:SS; MM/DD/YYYY HH:MM; MM/DD/YYYY; '
+                                          u'MM/DD/YY HH:MM:SS; MM/DD/YY HH:MM; MM/DD/YY'])
+        else:
+            self.fail("ValidationError was not properly raised")
+
+
+class TimeFieldTest(TestCase):
+    def test_valid_default_time_input_formats(self):
+        serializer = TimeObjectSerializer(data={'time': '04:31'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = TimeObjectSerializer(data={'time': '04:31:59'})
+        self.assertTrue(serializer.is_valid())
+
+    def test_valid_custom_time_input_formats(self):
+        serializer = TimeObjectCustomFormatSerializer(data={'time': '04 -- 31'})
+        self.assertTrue(serializer.is_valid())
+
+        serializer = TimeObjectCustomFormatSerializer(data={'time': '043159'})
+        self.assertTrue(serializer.is_valid())
+
+    def test_wrong_default_time_input_format(self):
+        serializer = TimeObjectSerializer(data={'time': 'something wrong'})
+        self.assertFalse(serializer.is_valid())
+        self.assertEquals(serializer.errors, {'time': [u'Time has wrong format. Use one of these formats instead: HH:MM:SS; HH:MM']})
+
+    def test_wrong_custom_time_input_format(self):
+        serializer = TimeObjectCustomFormatSerializer(data={'time': '04:31'})
+        self.assertFalse(serializer.is_valid())
+        self.assertEquals(serializer.errors, {'time': [u'Time has wrong format. Use one of these formats instead: HH -- MM; HHMMSS']})
+
+    def test_from_native(self):
         f = serializers.TimeField()
-        result = f.from_native('12:34:56.987654')
+        result = f.from_native('12:34:56')
 
-        self.assertEqual(datetime.time(12, 34, 56, 987654), result)
+        self.assertEqual(datetime.time(12, 34, 56), result)
 
-    def test_TimeField_from_native_datetime_time(self):
+    def test_from_native_datetime_time(self):
         """
         Make sure from_native() accepts a datetime.time instance.
         """
         f = serializers.TimeField()
         result = f.from_native(datetime.time(12, 34, 56))
+
         self.assertEqual(result, datetime.time(12, 34, 56))
 
-    def test_TimeField_from_native_empty(self):
+    def test_from_native_empty(self):
         f = serializers.TimeField()
         result = f.from_native('')
+
         self.assertEqual(result, None)
 
-    def test_TimeField_from_native_invalid_time(self):
+    def test_from_native_invalid_time(self):
         f = serializers.TimeField()
 
         try:
             f.from_native('12:69:12')
         except validators.ValidationError as e:
-            self.assertEqual(e.messages, ["'12:69:12' value has an invalid "
+            self.assertEqual(e.messages, ["Time has wrong format. Use one of these formats instead: HH:MM:SS; HH:MM"])
-                                          "format. It must be a valid time "
-                                          "in the HH:MM[:ss[.uuuuuu]] format."])
         else:
             self.fail("ValidationError was not properly raised")
-
-    def test_TimeFieldModelSerializer(self):
-        serializer = TimeFieldModelSerializer()
-        self.assertTrue(isinstance(serializer.fields['clock'], serializers.TimeField))

rest_framework/utils/dates.py

@@ -0,0 +1,14 @@
+def get_readable_date_format(date_format):
+    mapping = [("%Y", "YYYY"),
+               ("%y", "YY"),
+               ("%m", "MM"),
+               ("%b", "[Jan through Dec]"),
+               ("%B", "[January through December]"),
+               ("%d", "DD"),
+               ("%H", "HH"),
+               ("%M", "MM"),
+               ("%S", "SS"),
+               ("%f", "uuuuuu")]
+    for k, v in mapping:
+        date_format = date_format.replace(k, v)
+    return date_format