truncate output for wide dataframes

Author: MarcoGorelli

pandas/core/col.py

@@ -260,9 +260,14 @@ def col(col_name: Hashable) -> Expression:
 
     def func(df: DataFrame) -> Series:
         if col_name not in df.columns:
+            columns_list = df.columns.tolist()
+            if len(columns_list) > 10:
+                columns_hint = columns_list[:10] + ["..."]
+            else:
+                columns_hint = columns_list
             msg = (
                 f"Column '{col_name}' not found in given DataFrame.\n\n"
-                f"Hint: did you mean one of {df.columns.tolist()} instead?"
+                f"Hint: did you mean one of {columns_hint} instead?"
             )
             raise ValueError(msg)
         return df[col_name]

pandas/tests/test_col.py

@@ -67,9 +67,19 @@ def test_namespaces(
 
 
 def test_invalid() -> None:
-    df = pd.DataFrame({"a": [1, 2]})
-    with pytest.raises(ValueError, match="did you mean"):
-        df.assign(c=pd.col("b").mean())
+    df = pd.DataFrame({"a": [1, 2], "b": [3, 4]})
+    with pytest.raises(ValueError, match=r"did you mean one of \['a', 'b'\] instead"):
+        df.assign(c=pd.col("c").mean())
+    df = pd.DataFrame({f"col_{i}": [0] for i in range(11)})
+    msg = (
+        "did you mean one of "
+        r"\['col_0', 'col_1', 'col_2', 'col_3', "
+        "'col_4', 'col_5', 'col_6', 'col_7', "
+        r"'col_8', 'col_9', '\.\.\.'\] instead"
+    )
+    ""
+    with pytest.raises(ValueError, match=msg):
+        df.assign(c=pd.col("c").mean())
 
 
 def test_custom_accessor() -> None: