Support for partition_cols in to_parquet

Author: anjsudh

pandas/io/parquet.py

@@ -123,10 +123,16 @@ def write(self, df, path, compression='snappy',
                 table, path, compression=compression, **kwargs)
 
         else:
-            table = self.api.Table.from_pandas(df, **from_pandas_kwargs)
-            self.api.parquet.write_table(
-                table, path, compression=compression,
-                coerce_timestamps=coerce_timestamps, **kwargs)
+            if 'partition_cols' in kwargs and len(kwargs['partition_cols']) > 0:
+                table = self.api.Table.from_pandas(df)
+                self.api.parquet.write_to_dataset(
+                    table, path, compression=compression,
+                    coerce_timestamps=coerce_timestamps, **kwargs)
+            else:
+                table = self.api.Table.from_pandas(df)
+                self.api.parquet.write_table(
+                    table, path, compression=compression,
+                    coerce_timestamps=coerce_timestamps, **kwargs)
 
     def read(self, path, columns=None, **kwargs):
         path, _, _, should_close = get_filepath_or_buffer(path)