influxdata · xginn8 · Jun 30, 2018 · Jun 1, 2018
@@ -365,16 +365,18 @@ def _convert_dataframe_to_lines(self,

        # Make an array of formatted field keys and values
        field_df = dataframe[field_columns]
+        # Keep the positions where Null values are found
+        mask_null = field_df.isnull().values

        field_df = self._stringify_dataframe(field_df,
                                             numeric_precision,
                                             datatype='field')

-        def format_line(line):
-            line = line[~line.isnull()]  # drop None entries
-            return ",".join((line.index + '=' + line.values))
-
-        fields = field_df.apply(format_line, axis=1)
+        field_df = (field_df.columns.values + '=').tolist() + field_df
+        field_df[field_df.columns[1:]] = ',' + field_df[
+            field_df.columns[1:]]
+        field_df = field_df.where(~mask_null, '')  # drop Null entries
+        fields = field_df.sum(axis=1)
        del field_df

        # Generate line protocol string
@@ -388,9 +390,6 @@ def _stringify_dataframe(dframe, numeric_precision, datatype='field'):
        # Prevent modification of input dataframe
        dframe = dframe.copy()

-        # Keep the positions where Null values are found
-        mask_null = dframe.isnull().values
-
        # Find int and string columns for field-type data
        int_columns = dframe.select_dtypes(include=['integer']).columns
        string_columns = dframe.select_dtypes(include=['object']).columns
@@ -435,7 +434,6 @@ def _stringify_dataframe(dframe, numeric_precision, datatype='field'):

        dframe.columns = dframe.columns.astype(str)

-        dframe = dframe.where(~mask_null, None)
        return dframe

    def _datetime_to_epoch(self, datetime, time_precision='s'):