More specific error message, moved imports to top of files

Author: tomrod

pandas/io/sas/sasreader.py

@@ -1,7 +1,7 @@
 """
 Read SAS sas7bdat or xport files.
 """
-
+from pandas import compat
 
 def read_sas(filepath_or_buffer, format=None, index=None, encoding=None,
              chunksize=None, iterator=False):
@@ -29,11 +29,11 @@ def read_sas(filepath_or_buffer, format=None, index=None, encoding=None,
     DataFrame if iterator=False and chunksize=None, else SAS7BDATReader
     or XportReader
     """
-    from pandas import compat
     if format is None:
-        buffErr = "Format unrecognized. If buffer object, specify format"
+        buffer_error_msg = "If this is a buffer object rather\
+                than a string name, you must specify a format string"
         if not isinstance(filepath_or_buffer,compat.string_types):
-            raise TypeError(buffErr)
+            raise TypeError(buffer_error_msg)
         try:
             fname = filepath_or_buffer.lower()
             if fname.endswith(".xpt"):

pandas/io/tests/sas/test_sas.py

@@ -1,9 +1,9 @@
 import pandas.util.testing as tm
+from pandas.compat import StringIO
+from pandas import read_sas
 
 class TestSasBuff(tm.TestCase):
     def test_sas_buffer_format(self):
-        import StringIO
-        from pandas.io.sas.sasreader import read_sas
-        b = StringIO.StringIO("")
+        b = StringIO("")
         with self.assertRaises(TypeError):
             read_sas(b)