add default

narwhals-dev · Mar 28, 2024 · a1bf55e · a1bf55e
1 parent 7dc0368
commit a1bf55e
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/narwhals/functions.py b/narwhals/functions.py
@@ -12,7 +12,9 @@
 
 
 def concat(
-    items: Iterable[DataFrame | LazyFrame], *, how: Literal["horizontal", "vertical"]
+    items: Iterable[DataFrame | LazyFrame],
+    *,
+    how: Literal["horizontal", "vertical"] = "vertical",
 ) -> DataFrame | LazyFrame:
     if how not in ("horizontal", "vertical"):
         raise NotImplementedError(