Python 3 fixes for fields/forms

This isn't intended to be exhaustive, I just fixed what I needed.

fusionbox/forms/fields.py

@@ -8,6 +8,7 @@
 import calendar
 import datetime
 import re
+import six
 from functools import partial
 
 import phonenumbers
@@ -243,7 +244,7 @@ def __init__(self, *args, **kwargs):
         super(CCNumberField, self).__init__(*args, **kwargs)
 
     def clean(self, value):
-        if isinstance(value, basestring):
+        if isinstance(value, six.string_types):
             value = re.sub('\D', '', value)
         number = super(CCNumberField, self).clean(value)
         return number

fusionbox/forms/forms.py

@@ -1,8 +1,12 @@
-import StringIO
 import copy
 import csv
 import urllib
 
+try:
+    from StringIO import StringIO
+except ImportError:
+    from io import StringIO
+
 from django import forms
 from django.core.exceptions import ValidationError
 from django.forms.util import ErrorList, ErrorDict
@@ -345,7 +349,7 @@ def pre_sort(self, qs):
         """
         Hook for doing pre-sort modification of the queryset.
 
-        Runs regardless 
+        Runs regardless
         """
         return qs
 
@@ -656,7 +660,7 @@ def csv_content(self):
             csv_data.append([unicode(csv_getvalue(obj, column)).encode('utf-8') for column in csv_columns])
 
         # Create buffer with csv content
-        content = StringIO.StringIO()
+        content = StringIO()
         writer = csv.writer(content)
         writer.writerow(csv_headers)
         writer.writerows(csv_data)