Enabled ruff rule EM101

Author: Spaarsh

benchmarks/db-benchmark/join-datafusion.py

@@ -57,7 +57,8 @@ def ans_shape(batches):
     os.path.join("data", y_data_name[2] + ".csv"),
 ]
 if len(src_jn_y) != 3:
-    raise Exception("Something went wrong in preparing files used for join")
+    error_msg = "Something went wrong in preparing files used for join"
+    raise Exception(error_msg)
 
 print(
     "loading datasets "

pyproject.toml

@@ -83,7 +83,7 @@ ignore = [
     #"PT001",
     # "ANN204",
     # "B008",
-    "EM101",
+    # "EM101",
     "PLR0913",
     "PLR1714",
     "ANN201",

python/datafusion/dataframe.py

@@ -529,18 +529,17 @@ def join(
 
         if on is not None:
             if left_on is not None or right_on is not None:
-                raise ValueError(
-                    "`left_on` or `right_on` should not provided with `on`"
-                )
+                error_msg = "`left_on` or `right_on` should not provided with `on`"
+                raise ValueError(error_msg)
             left_on = on
             right_on = on
         elif left_on is not None or right_on is not None:
             if left_on is None or right_on is None:
-                raise ValueError("`left_on` and `right_on` should both be provided.")
+                error_msg = "`left_on` and `right_on` should both be provided."
+                raise ValueError(error_msg)
         else:
-            raise ValueError(
-                "either `on` or `left_on` and `right_on` should be provided."
-            )
+            error_msg = "either `on` or `left_on` and `right_on` should be provided."
+            raise ValueError(error_msg)
         if isinstance(left_on, str):
             left_on = [left_on]
         if isinstance(right_on, str):

python/datafusion/expr.py

@@ -454,9 +454,8 @@ def cast(
             try:
                 to = self._to_pyarrow_types[to]
             except KeyError:
-                raise TypeError(
-                    "Expected instance of pyarrow.DataType or builtins.type"
-                )
+                error_msg = "Expected instance of pyarrow.DataType or builtins.type"
+                raise TypeError(error_msg)
 
         return Expr(self.expr.cast(to))