drop python 2.7 support (fixes #48)

Author: sheppard

rest_pandas/renderers.py

@@ -2,16 +2,8 @@
 from rest_framework import status
 from tempfile import mkstemp
 from pandas import DataFrame
-
-try:
-    # Python 2 (uses str)
-    from StringIO import StringIO
-except ImportError:
-    # Python 3 (Python 2 equivalent uses unicode)
-    from io import StringIO
-
+from io import StringIO, BytesIO
 import os
-from io import BytesIO
 
 
 RESPONSE_ERROR = (
@@ -189,7 +181,7 @@ def render_dataframe(self, data, name, *args, **kwargs):
         if kwargs.get('orient') == 'records-index':
             kwargs['orient'] = 'records'
             data.reset_index(inplace=True)
-        return super(PandasJSONRenderer, self).render_dataframe(
+        return super().render_dataframe(
             data, name, *args, **kwargs
         )
 

rest_pandas/serializers.py

@@ -43,7 +43,7 @@ def transform_dataframe(self, dataframe):
 
     @property
     def data(self):
-        data = super(serializers.ListSerializer, self).data
+        data = super().data
         if isinstance(data, DataFrame) or data:
             dataframe = self.get_dataframe(data)
             return self.transform_dataframe(dataframe)
@@ -53,7 +53,7 @@ def data(self):
     def to_representation(self, data):
         if isinstance(data, DataFrame):
             return data
-        return super(PandasSerializer, self).to_representation(data)
+        return super().to_representation(data)
 
     @property
     def model_serializer(self):

rest_pandas/views.py

@@ -126,7 +126,7 @@ class PandasView(PandasViewBase, ListAPIView):
     """
 
     def list(self, request, *args, **kwargs):
-        response = super(PandasView, self).list(request, *args, **kwargs)
+        response = super().list(request, *args, **kwargs)
         return self.update_pandas_headers(response)
 
 
@@ -135,5 +135,5 @@ class PandasViewSet(PandasViewBase, ListModelMixin, GenericViewSet):
     Pandas-capable model ViewSet (list only)
     """
     def list(self, request, *args, **kwargs):
-        response = super(PandasViewSet, self).list(request, *args, **kwargs)
+        response = super().list(request, *args, **kwargs)
         return self.update_pandas_headers(response)