Add deprecation warning

Author: SabineHaas

doc/whatsnew/v0-1-2.txt

@@ -20,6 +20,7 @@ Deprecations
 ############
 * installed_power is deprecated, use nominal_power instead.
 * wake_losses_model is deprecated, will be defined by the type of wind_farm_efficiency
+* parameters data_source and fetch_curve are deprecated, data source and fetching will be defined by the parameters power_coefficient_curve, power_curve and nominal_power in the future. The default values ('oedb') will lead to the same behaviour like the current default values (None, data_source='oedb').
 
 Contributors
 ############

windpowerlib/wind_turbine.py

@@ -13,6 +13,7 @@
 import sys
 import requests
 import os
+import warnings
 
 
 class WindTurbine(object):
@@ -110,6 +111,14 @@ def __init__(self, name, hub_height, rotor_diameter=None,
                  nominal_power=None, fetch_curve=None, coordinates=None,
                  data_source='oedb', **kwargs):
 
+        warnings.warn(
+            "parameters data_source and fetch_curve are deprecated, data "
+            "source and fetching will be defined by the parameters "
+            "power_coefficient_curve, power_curve and nominal_power in the "
+            "future. The default values ('oedb') will lead to the same "
+            "behaviour like the current default values "
+            "(None, data_source='oedb').", FutureWarning)
+
         self.name = name
         self.hub_height = hub_height
         self.rotor_diameter = rotor_diameter