fix: use pandas.concat() instead of deprecated DataFrame.append() (#407)

Author: bednar

CHANGELOG.md

@@ -35,6 +35,7 @@ This release introduces a support for new version of InfluxDB OSS API definition
 
 ### Bug Fixes
 1. [#408](https://github.com/influxdata/influxdb-client-python/pull/408): Improve error message when the client cannot find organization by name
+1. [#407](https://github.com/influxdata/influxdb-client-python/pull/407): Use `pandas.concat()` instead of deprecated `DataFrame.append()` [DataFrame]
 
 ## 1.25.0 [2022-01-20]
 

influxdb_client/client/flux_csv_parser.py

@@ -187,7 +187,7 @@ def _prepare_data_frame(self):
             _temp_df = _temp_df.set_index(self._data_frame_index)
 
         # Append data
-        return self._data_frame.astype(_temp_df.dtypes).append(_temp_df)
+        return pd.concat([self._data_frame.astype(_temp_df.dtypes), _temp_df])
 
     def parse_record(self, table_index, table, csv):
         """Parse one record."""