feat(config): add explicit validation for required configuration fields

Author: Sourish-07

qlib/config.py

@@ -62,16 +62,33 @@ class QSettings(BaseSettings):
 
 class Config:
     def __init__(self, default_conf):
-        self.__dict__["_default_config"] = copy.deepcopy(default_conf)  # avoiding conflicts with __getattr__
+        self.__dict__["_default_config"] = copy.deepcopy(default_conf)
         self.reset()
 
+    def validate(self):
+        errors = []
+
+        if not self.get("provider_uri"):
+            errors.append(
+                "provider_uri must be set (e.g. ~/.qlib/qlib_data or a valid path)"
+            )
+
+        if not self.get("region"):
+            errors.append(
+                "region must be specified (e.g. 'cn', 'us')"
+            )
+
+        if errors:
+            raise ValueError(
+                "Invalid Qlib configuration:\n- " + "\n- ".join(errors)
+            )
+
     def __getitem__(self, key):
         return self.__dict__["_config"][key]
 
     def __getattr__(self, attr):
         if attr in self.__dict__["_config"]:
             return self.__dict__["_config"][attr]
-
         raise AttributeError(f"No such `{attr}` in self._config")
 
     def get(self, key, default=None):
@@ -109,14 +126,20 @@ def set_conf_from_C(self, config_c):
 
     @staticmethod
     def register_from_C(config, skip_register=True):
-        from .utils import set_log_with_config  # pylint: disable=C0415
+        from .utils import set_log_with_config
 
         if C.registered and skip_register:
             return
 
+        
         C.set_conf_from_C(config)
+
+
+        C.validate()
+
         if C.logging_config:
             set_log_with_config(C.logging_config)
+
         C.register()
 
 
@@ -523,4 +546,4 @@ def registered(self):
 
 
 # global config
-C = QlibConfig(_default_config)
+C = QlibConfig(_default_config)

qlib/tests/test_config_validation.py

@@ -0,0 +1,17 @@
+import pytest
+from qlib.config import C, Config
+
+
+def test_missing_provider_uri_raises():
+    
+    default_conf = {
+        "provider_uri": None,
+        "region": "us"
+    }
+
+    cfg = Config(default_conf)
+
+    with pytest.raises(ValueError) as exc:
+        cfg.validate()
+
+    assert "provider_uri must be set" in str(exc.value)