FIX dask

Author: lorentzenchr

python-package/lightgbm/dask.py

@@ -323,8 +323,8 @@ def _train_part(
         local_eval_X = None
         local_eval_y = None
     else:
-        local_eval_X = ((X for X, y in local_eval_set),)
-        local_eval_y = ((y for X, y in local_eval_set),)
+        local_eval_X = tuple(X for X, y in local_eval_set)
+        local_eval_y = tuple(y for X, y in local_eval_set)
 
     model = model_factory(**params)
     if remote_socket is not None:

python-package/lightgbm/sklearn.py

@@ -500,6 +500,8 @@ def _validate_eval_set_Xy(eval_set, eval_X, eval_y):
     if eval_set is not None:
         msg = "The argument 'eval_set' is deprecated, use 'eval_X' and 'eval_y' instead."
         warnings.warn(msg, category=LGBMDeprecationWarning, stacklevel=2)
+        if eval_X is not None or eval_y is not None:
+            raise ValueError("Specify either 'eval_set' or 'eval_X' and 'eval_y', but not both.")
         return eval_set
     if (eval_X is None) != (eval_y is None):
         raise ValueError("You must specify eval_X and eval_y, not just one of them.")
@@ -508,10 +510,10 @@ def _validate_eval_set_Xy(eval_set, eval_X, eval_y):
             raise ValueError("If eval_X is a tuple, y_val must be a tuple of same length, and vice versa.")
         if isinstance(eval_X, tuple) and len(eval_X) != len(eval_y):
             raise ValueError("If eval_X is a tuple, y_val must be a tuple of same length, and vice versa.")
-        if not isinstance(eval_X, tuple):
-            eval_set = (eval_X, eval_y)
-        else:
+        if isinstance(eval_X, tuple):
             eval_set = list(zip(eval_X, eval_y))
+        else:
+            eval_set = [(eval_X, eval_y)]
     return eval_set