save attr str var to numeric (#4)

hydrodataset/camels.py

@@ -1,10 +1,10 @@
 """
 Author: Wenyu Ouyang
 Date: 2022-01-05 18:01:11
-LastEditTime: 2023-10-18 17:54:32
+LastEditTime: 2023-11-20 20:08:14
 LastEditors: Wenyu Ouyang
 Description: Read Camels Series ("AUStralia", "BRazil", "ChiLe", "GreatBritain", "UnitedStates") datasets
-FilePath: \hydrodataset\hydrodataset\camels.py
+FilePath: /hydrodataset/hydrodataset/camels.py
 Copyright (c) 2021-2022 Wenyu Ouyang. All rights reserved.
 """
 import json
@@ -1523,6 +1523,7 @@ def cache_attributes_xrdataset(self):
 
         attrs_df = pd.concat(attrs.values(), axis=1)
 
+        # fix station names
         def fix_station_nm(station_nm):
             name = station_nm.title().rsplit(" ", 1)
             name[0] = name[0] if name[0][-1] == "," else f"{name[0]},"
@@ -1535,6 +1536,17 @@ def fix_station_nm(station_nm):
         obj_cols = attrs_df.columns[attrs_df.dtypes == "object"]
         for c in obj_cols:
             attrs_df[c] = attrs_df[c].str.strip().astype(str)
+
+        # transform categorical variables to numeric
+        categorical_mappings = {}
+        for column in attrs_df.columns:
+            if attrs_df[column].dtype == "object":
+                attrs_df[column] = attrs_df[column].astype("category")
+                categorical_mappings[column] = dict(
+                    enumerate(attrs_df[column].cat.categories)
+                )
+                attrs_df[column] = attrs_df[column].cat.codes
+
         # unify id to basin
         attrs_df.index.name = "basin"
         # We use xarray dataset to cache all data
@@ -1605,6 +1617,12 @@ def fix_station_nm(station_nm):
         for var_name in units_dict:
             if var_name in ds_from_df.data_vars:
                 ds_from_df[var_name].attrs["units"] = units_dict[var_name]
+
+        # Assign categorical mappings to the variables in the Dataset
+        for column in ds_from_df.data_vars:
+            if column in categorical_mappings:
+                mapping_str = categorical_mappings[column]
+                ds_from_df[column].attrs["category_mapping"] = str(mapping_str)
         return ds_from_df
 
     def cache_streamflow_xrdataset(self):