use django csv handling

questionnaire/utils.py

@@ -72,33 +72,3 @@ if __name__ == "__main__":
     import doctest
     doctest.testmod()
 
-class UnicodeWriter:
-    """
-    COPIED from http://docs.python.org/library/csv.html example:
-
-    A CSV writer which will write rows to CSV file "f",
-    which is encoded in the given encoding.
-    """
-
-    def __init__(self, f, dialect=csv.excel, encoding="utf-8", **kwds):
-        # Redirect output to a queue
-        self.queue = StringIO()
-        self.writer = csv.writer(self.queue, dialect=dialect, **kwds)
-        self.stream = f
-        self.encoder = codecs.getincrementalencoder(encoding)()
-
-    def writerow(self, row):
-        self.writer.writerow([unicodestr(s).encode("utf-8") for s in row])
-        # Fetch UTF-8 output from the queue ...
-        data = self.queue.getvalue()
-        data = data.decode("utf-8")
-        # ... and reencode it into the target encoding
-        data = self.encoder.encode(data)
-        # write to the target stream
-        self.stream.write(data)
-        # empty queue
-        self.queue.truncate(0)
-
-    def writerows(self, rows):
-        for row in rows:
-            self.writerow(row)

questionnaire/views.py

@@ -4,6 +4,7 @@ import json
 import logging
 from six import text_type as unicodestr
 import tempfile
+import csv
 
 from compat import commit_on_success, commit, rollback
 from functools import cmp_to_key
@@ -31,7 +32,7 @@ from .models import (
 )
 from .forms import NewLandingForm
 from .parsers import BooleanParser
-from .utils import numal_sort, split_numal, UnicodeWriter
+from .utils import numal_sort, split_numal
 from .run import (
     add_answer, delete_answer, get_runinfo, get_question,
     question_satisfies_checks, questionset_satisfies_checks,
@@ -732,22 +733,19 @@ def export_csv(request, qid,
     if answer_filter is None and not request.user.has_perm("questionnaire.export"):
         return HttpResponse('Sorry, you do not have export permissions', content_type="text/plain")
 
-    fd = tempfile.TemporaryFile()
+    response = HttpResponse(content_type='text/csv')
+    response['Content-Disposition'] = 'attachment; filename="answers-%s-%s.csv"' % (qid, filecode)
 
     questionnaire = get_object_or_404(Questionnaire, pk=int(qid))
     headings, answers = answer_export(questionnaire, answer_filter=answer_filter)
 
-    writer = UnicodeWriter(fd)
+    writer = csv.writer(response, dialect='excel')
     writer.writerow(extra_headings + headings)
     for subject, run, answer_row in answers:
         row = extra_entries(subject, run) + [
             a if a else '--' for a in answer_row]
         writer.writerow(row)
-    fd.seek(0)
 
-    response = HttpResponse(fd, content_type="text/csv")
-    response['Content-Length'] = fd.tell()
-    response['Content-Disposition'] = 'attachment; filename="answers-%s-%s.csv"' % (qid, filecode)
     return response