Topic/add support for ordering

djqscsv/djqscsv.py

@@ -23,7 +23,8 @@ class CSVException(Exception):
 
 
 def render_to_csv_response(queryset, filename=None, append_datestamp=False,
-                           field_header_map=None, use_verbose_names=True):
+                           field_header_map=None, use_verbose_names=True,
+                           field_order=None):
     """
     provides the boilerplate for making a CSV http response.
     takes a filename or generates one from the queryset's model.
@@ -40,13 +41,13 @@ def render_to_csv_response(queryset, filename=None, append_datestamp=False,
     response['Content-Disposition'] = 'attachment; filename=%s;' % filename
     response['Cache-Control'] = 'no-cache'
 
-    write_csv(queryset, response, field_header_map, use_verbose_names)
+    write_csv(queryset, response, field_header_map, use_verbose_names, field_order)
 
     return response
 
 
 def write_csv(queryset, file_obj, field_header_map=None,
-              use_verbose_names=True):
+              use_verbose_names=True, field_order=None):
     """
     The main worker function. Writes CSV data to a file object based on the
     contents of the queryset.
@@ -64,16 +65,25 @@ def write_csv(queryset, file_obj, field_header_map=None,
 
     try:
         field_names = values_qs.field_names
-        extra_columns = list(values_qs.query.extra_select)
-        if extra_columns:
-            # TODO: provide actual ordering
-            field_names += extra_columns
 
     except AttributeError:
         # in django1.5, empty querysets trigger
         # this exception, but not django 1.6
         raise CSVException("Empty queryset provided to exporter.")
 
+    extra_columns = list(values_qs.query.extra_select)
+    if extra_columns:
+        field_names += extra_columns
+
+    if field_order:
+        # go through the field_names and put the ones
+        # that appear in the ordering list first
+        field_names = ([field for field in field_order
+                       if field in field_names] +
+                       [field for field in field_names
+                        if field not in field_order])
+
+
     writer = csv.DictWriter(file_obj, field_names)
 
     # verbose_name defaults to the raw field name, so in either case
@@ -137,7 +147,7 @@ def _sanitize_value(value):
 
     obj = {}
     for key, val in six.iteritems(record):
-        if val:
+        if val is not None:
             obj[_sanitize_value(key)] = _sanitize_value(val)
 
     return obj

setup.py

@@ -5,7 +5,7 @@
 
 setup(
     name='django-queryset-csv',
-    version='0.2.2',
+    version='0.2.3',
     description='A simple python module for writing querysets to csv',
     long_description=open('README.md').read(),
     author=author,

test_app/djqscsv_tests/tests.py

@@ -4,6 +4,7 @@
 from django import VERSION as DJANGO_VERSION
 
 import csv
+import itertools
 
 from .context import djqscsv
 
@@ -50,12 +51,12 @@ def test_non_csv_raises_2(self):
 
 class SanitizeUnicodeRecordTests(TestCase):
     def test_sanitize(self):
-        record = {'name': 'Ged',
-                  'nickname': u'\ufeffSparrowhawk'}
+        record = {'name': 'Tenar',
+                  'nickname': u'\ufeffThe White Lady of Gont'}
         sanitized = djqscsv._sanitize_unicode_record(record)
         self.assertEqual(sanitized,
-                         {'name': 'Ged',
-                          'nickname': '\xef\xbb\xbfSparrowhawk'})
+                         {'name': 'Tenar',
+                          'nickname': '\xef\xbb\xbfThe White Lady of Gont'})
 
 
 class AppendDatestampTests(TestCase):
@@ -89,37 +90,46 @@ def test_generate_filename(self):
                                  r'person_export_[0-9]{8}.csv')
 
 
-class WriteCSVDataTests(TestCase):
+class CSVTestCase(TestCase):
+
+    def assertMatchesCsv(self, csv_file, expected_data):
+        csv_data = csv.reader(csv_file)
+        iteration_happened = False
+        test_pairs = itertools.izip_longest(csv_data, expected_data,
+                                            fillvalue=[])
+        for csv_row, expected_row in test_pairs:
+            iteration_happened = True
+            self.assertEqual(csv_row, expected_row)
+
+        self.assertTrue(iteration_happened, "The CSV does not contain data.")
+
+
+class WriteCSVDataTests(CSVTestCase):
 
     def setUp(self):
         self.qs = create_people_and_get_queryset()
 
         self.full_verbose_csv = [
             ['\xef\xbb\xbfID', 'Person\'s name', 'address', 'Info on Person'],
             ['1', 'vetch', 'iffish', 'wizard'],
-            ['2', 'nemmerle', 'roke', 'arch mage']]
+            ['2', 'nemmerle', 'roke', 'deceased arch mage'],
+            ['3', 'ged', 'gont', 'former arch mage']]
 
         self.full_csv = [['\xef\xbb\xbfid', 'name', 'address', 'info'],
                          ['1', 'vetch', 'iffish', 'wizard'],
-                         ['2', 'nemmerle', 'roke', 'arch mage']]
+                         ['2', 'nemmerle', 'roke', 'deceased arch mage'],
+                         ['3', 'ged', 'gont', 'former arch mage']]
 
         self.limited_verbose_csv = [
             ['\xef\xbb\xbfPerson\'s name', 'address', 'Info on Person'],
             ['vetch', 'iffish', 'wizard'],
-            ['nemmerle', 'roke', 'arch mage']]
+            ['nemmerle', 'roke', 'deceased arch mage'],
+            ['ged', 'gont', 'former arch mage']]
 
         self.limited_csv = [['\xef\xbb\xbfname', 'address', 'info'],
                             ['vetch', 'iffish', 'wizard'],
-                            ['nemmerle', 'roke', 'arch mage']]
-
-    def assertMatchesCsv(self, csv_file, expected_data):
-        csv_data = csv.reader(csv_file)
-        iteration_happened = False
-        for csv_row, expected_row in zip(csv_data, expected_data):
-            iteration_happened = True
-            self.assertEqual(csv_row, expected_row)
-
-        self.assertTrue(iteration_happened, "The CSV does not contain data.")
+                            ['nemmerle', 'roke', 'deceased arch mage'],
+                            ['ged', 'gont', 'former arch mage']]
 
     def test_write_csv_full_terse(self):
         obj = StringIO()
@@ -187,3 +197,31 @@ def test_empty_queryset(self):
             self.assertEqual(obj.getvalue(),
                              '\xef\xbb\xbfid,name,address,info\r\n')
 
+
+class OrderingTests(CSVTestCase):
+    def setUp(self):
+        self.qs = create_people_and_get_queryset().extra(
+            select={'Most Powerful':"info LIKE '%arch mage%'"})
+
+        self.csv_with_extra = [
+            ['\xef\xbb\xbfID', 'Person\'s name', 'address',
+             'Info on Person', 'Most Powerful'],
+            ['1', 'vetch', 'iffish', 'wizard', '0'],
+            ['2', 'nemmerle', 'roke', 'deceased arch mage', '1'],
+            ['3', 'ged', 'gont', 'former arch mage', '1']]
+
+        self.custom_order_csv = [[row[0], row[4]] + row[1:4]
+                                 for row in self.csv_with_extra]
+
+    def test_extra_select(self):
+        obj = StringIO()
+        djqscsv.write_csv(self.qs, obj)
+        csv_file = filter(None, obj.getvalue().split('\n'))
+        self.assertMatchesCsv(csv_file, self.csv_with_extra)
+
+    def test_extra_select_ordering(self):
+        obj = StringIO()
+        djqscsv.write_csv(self.qs, obj, field_order=['id', 'Most Powerful'])
+        csv_file = filter(None, obj.getvalue().split('\n'))
+        self.assertMatchesCsv(csv_file, self.custom_order_csv)
+

test_app/djqscsv_tests/util.py

@@ -3,7 +3,9 @@
 def create_people_and_get_queryset():
     Person.objects.create(name='vetch', address='iffish', info='wizard')
     Person.objects.create(name='nemmerle', address='roke',
-                              info='arch mage')
+                              info='deceased arch mage')
+    Person.objects.create(name='ged', address='gont',
+                              info='former arch mage')
 
     return Person.objects.all()