default to orderbyall given no cols

Author: sfc-gh-mayliu

src/snowflake/snowpark/dataframe.py

@@ -2153,7 +2153,8 @@ def sort(
             -------------
             <BLANKLINE>
 
-            >>> df.sort(ascending=False).show()
+            >>> # Sort by all columns (ORDER BY ALL) - no columns specified
+            >>> df.sort([], ascending=False).show()
             -------------
             |"A"  |"B"  |
             -------------
@@ -2182,13 +2183,9 @@ def sort(
             The aliases ``order_by()`` and ``orderBy()`` have the same behavior.
         """
 
-        is_order_by_all = not cols
-
         # This code performs additional type checks, run first.
         exprs = self._convert_cols_to_exprs("sort()", *cols)
-        if not is_order_by_all:
-            if not exprs:
-                raise ValueError("sort() needs at least one sort expression.")
+        is_order_by_all = not cols or not exprs
 
         if (
             is_order_by_all