Added a check for the 'seasons' argument in 'interface.py'. The check function...

Added a check for the 'seasons' argument in 'interface.py'. The check function is included in 'input_checks.py'.

toarstats/input_checks.py

@@ -5,6 +5,7 @@ check_sampling - check the given sampling argument
 check_statistics - check the given statistics argument
 check_data - check the given data argument
 check_metadata - check the given metadata argument
+check_seasons - check the given seasons argument
 """
 
 from collections import namedtuple
@@ -14,7 +15,7 @@ import pandas as pd
 
 from toarstats import ozone_metrics
 from toarstats import stats
-from toarstats.stats_utils import CLIMATIC_ZONE, RSTAGS
+from toarstats.stats_utils import CLIMATIC_ZONE, RSTAGS, SEASON_DICT
 
 
 def check_sampling(sampling_in):
@@ -147,3 +148,28 @@ def check_metadata(metadata_in, station_lat_in, station_lon_in,
     else:
         metadata_dict["station_climatic_zone"] = None
     return namedtuple("Metadata", metadata_dict)(**metadata_dict)
+
+
+def check_seasons(seasons_in):
+    """Check the given seasons argument.
+
+    :param seasons_in: the given seasons argument
+
+    :return: The processed seasons argument or None if there was a
+             problem while processing the given seasons argument
+    """
+    if not isinstance(seasons_in, (list, str)):
+        return None
+    seasons_in_list = (
+        [seasons_in] if isinstance(seasons_in, str) else seasons_in
+    )
+    seasons_out = []
+    for season in seasons_in_list:
+        if not isinstance(season, str):
+            continue
+        season = season.strip()
+        if season in SEASON_DICT and season not in seasons_out:
+            seasons_out.append(season)
+    if not seasons_out:
+        return None
+    return seasons_out

toarstats/interface.py

@@ -5,7 +5,7 @@ calculate_statistics - calculate the requested statistics
 """
 
 from toarstats.input_checks import (check_data, check_metadata, check_sampling,
-                                    check_statistics)
+                                    check_seasons, check_statistics)
 
 
 def calculate_statistics(sampling, statistics, data=None, metadata=None,
@@ -96,3 +96,4 @@ def calculate_statistics(sampling, statistics, data=None, metadata=None,
     data_frame = check_data(data, datetimes, values)
     metadata_tuple = check_metadata(metadata, station_lat, station_lon,
                                     station_climatic_zone)
+    seasons_list = check_seasons(seasons)