Fixed #31487 -- Added precision argument to Round().

docs/ref/models/database-functions.txt

@@ -1147,18 +1147,19 @@ Returns a random value in the range ``0.0 ≤ x < 1.0``.
 ``Round``
 ---------
 
-.. class:: Round(expression, **extra)
+.. class:: Round(expression, precision=0, **extra)
 
-Rounds a numeric field or expression to the nearest integer. Whether half
+Rounds a numeric field or expression to ``precision`` (must be an integer)
+decimal places. By default, it rounds to the nearest integer. Whether half
 values are rounded up or down depends on the database.
 
 Usage example::
 
     >>> from django.db.models.functions import Round
-    >>> Vector.objects.create(x=5.4, y=-2.3)
-    >>> vector = Vector.objects.annotate(x_r=Round('x'), y_r=Round('y')).get()
+    >>> Vector.objects.create(x=5.4, y=-2.37)
+    >>> vector = Vector.objects.annotate(x_r=Round('x'), y_r=Round('y', precision=1)).get()
     >>> vector.x_r, vector.y_r
-    (5.0, -2.0)
+    (5.0, -2.4)
 
 It can also be registered as a transform. For example::
 
@@ -1168,6 +1169,10 @@ It can also be registered as a transform. For example::
     >>> # Get vectors whose round() is less than 20
     >>> vectors = Vector.objects.filter(x__round__lt=20, y__round__lt=20)
 
+.. versionchanged:: 4.0
+
+    The ``precision`` argument was added.
+
 ``Sign``
 --------
 

docs/releases/4.0.txt

@@ -222,6 +222,10 @@ Models
   whether the queryset contains the given object. This tries to perform the
   query in the simplest and fastest way possible.
 
+* The new ``precision`` argument of the
+  :class:`Round() <django.db.models.functions.Round>` database function allows
+  specifying the number of decimal places after rounding.
+
 Requests and Responses
 ~~~~~~~~~~~~~~~~~~~~~~