solve PEP8 errors

Author: rushabh-v

pandas/core/series.py

@@ -2586,7 +2586,7 @@ def combine(self, other, func, fill_value=None):
         if is_categorical_dtype(self.values):
             pass
         elif is_extension_array_dtype(self.values):
-            if len(new_values)>0:
+            if len(new_values) > 0:
                 if not is_bool(new_values[0]):
                     # The function can return something of any type, so check
                     # if the type is compatible with the calling EA.