fix: add Pandas as optional dependency (#43)

Author: bednar

README.rst

@@ -16,10 +16,6 @@ influxdb-client-python
    :target: https://circleci.com/gh/influxdata/influxdb-client-python
    :alt: CI status
 
-.. image:: https://img.shields.io/codecov/c/github/influxdata/influxdb-client-python.svg
-   :target: https://codecov.io/gh/influxdata/influxdb-client-python
-   :alt: Coverage
-
 .. image:: https://img.shields.io/pypi/v/influxdb-client.svg
    :target: https://pypi.org/project/influxdb-client/
    :alt: PyPI package
@@ -375,6 +371,8 @@ Pandas DataFrame
 """"""""""""""""
 .. marker-pandas-start
 
+.. note:: For DataFrame querying you should install Pandas dependency via ``pip install influxdb-client[extra]``.
+
 .. note:: Note that if a query returns more then one table then the client generates a ``DataFrame`` for each of them.
 
 The ``client`` is able to retrieve data in `Pandas DataFrame <https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.html>`_ format thought ``query_data_frame``:

extra-requirements.txt

@@ -0,0 +1 @@
+pandas>=0.25.3

influxdb_client/client/flux_csv_parser.py

@@ -5,7 +5,6 @@
 from typing import List
 
 import ciso8601
-from pandas import DataFrame
 from urllib3 import HTTPResponse
 
 from influxdb_client.client.flux_table import FluxTable, FluxColumn, FluxRecord
@@ -104,7 +103,8 @@ def _parse_flux_response(self):
                     start_new_table = False
                     # Create DataFrame with default values
                     if self._serialization_mode is FluxSerializationMode.dataFrame:
-                        self._data_frame = DataFrame(data=[], columns=[], index=None)
+                        from ..extras import pd
+                        self._data_frame = pd.DataFrame(data=[], columns=[], index=None)
                         for column in table.columns:
                             self._data_frame[column.label] = column.default_value
                         pass

influxdb_client/client/query_api.py

@@ -2,8 +2,6 @@
 import csv
 from typing import List, Generator, Any
 
-from pandas import DataFrame
-
 from influxdb_client import Dialect
 from influxdb_client import Query, QueryService
 from influxdb_client.client.flux_csv_parser import FluxCsvParser, FluxSerializationMode
@@ -104,6 +102,9 @@ def query_data_frame(self, query: str, org=None, data_frame_index: List[str] = N
         :param data_frame_index: the list of columns that are used as DataFrame index
         :return:
         """
+
+        from ..extras import pd
+
         if org is None:
             org = self._influxdb_client.org
 
@@ -115,7 +116,7 @@ def query_data_frame(self, query: str, org=None, data_frame_index: List[str] = N
         _dataFrames = list(_parser.generator())
 
         if len(_dataFrames) == 0:
-            return DataFrame(columns=[], index=None)
+            return pd.DataFrame(columns=[], index=None)
         elif len(_dataFrames) == 1:
             return _dataFrames[0]
         else:

influxdb_client/extras.py

@@ -0,0 +1,6 @@
+try:
+    import pandas as pd
+except ModuleNotFoundError as err:
+    raise ImportError(f"`query_data_frame` requires Pandas which couldn't be imported due: {err}")
+
+__all__ = ['pd']

requirements.txt

@@ -6,4 +6,3 @@ setuptools >= 21.0.0
 urllib3 >= 1.15.1
 ciso8601>=2.1.1
 pytz>=2019.1
-pandas>=0.25.3

scripts/ci-test.sh

@@ -7,6 +7,7 @@ set -e
 #
 python --version
 pip install -r requirements.txt
+pip install -r extra-requirements.txt
 pip install -r test-requirements.txt
 pip install pytest pytest-cov
 pip install twine

setup.py

@@ -10,6 +10,9 @@
 with open('test-requirements.txt', 'r') as f:
     test_requires = [x.strip() for x in f if x.strip()]
 
+with open('extra-requirements.txt', 'r') as f:
+    extra_requires = [x.strip() for x in f if x.strip()]
+
 with open('README.rst', 'r') as f:
     readme = f.read()
 
@@ -29,6 +32,7 @@
     keywords=["InfluxDB", "InfluxDB Python Client"],
     tests_require=test_requires,
     install_requires=requires,
+    extras_require={'extra': extra_requires},
     long_description_content_type="text/x-rst",
     packages=find_packages(),
     test_suite='tests',

test-requirements.txt

@@ -6,5 +6,3 @@ randomize>=0.13
 pytest>=5.0.0
 httpretty>=0.9.6
 psutil>=5.6.3
-pandas>=0.25.3
-