Merge 67cf8b3 into 8b764a2

more-itertools · Nov 12, 2019 · 25bbe59 · 25bbe59
2 parents 8b764a2 + 67cf8b3
commit 25bbe59
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/more_itertools/more.py b/more_itertools/more.py
@@ -1580,8 +1580,8 @@ def groupby_transform(iterable, keyfunc=None, valuefunc=None):
     duplicate groups, you should sort the iterable by the key function.
 
     """
-    valuefunc = (lambda x: x) if valuefunc is None else valuefunc
-    return ((k, map(valuefunc, g)) for k, g in groupby(iterable, keyfunc))
+    res = groupby(iterable, keyfunc)
+    return ((k, map(valuefunc, g)) for k, g in res) if valuefunc else res
 
 
 def numeric_range(*args):