bpo-29677: DOC: clarify documentation for `round` (GH-877)
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index 2c0ea71..90fb07a 100644
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -1254,9 +1254,9 @@
.. function:: round(number[, ndigits])
- Return the floating point value *number* rounded to *ndigits* digits after
- the decimal point. If *ndigits* is omitted or is ``None``, it returns the
- nearest integer to its input. Delegates to ``number.__round__(ndigits)``.
+ Return *number* rounded to *ndigits* precision after the decimal
+ point. If *ndigits* is omitted or is ``None``, it returns the
+ nearest integer to its input.
For the built-in types supporting :func:`round`, values are rounded to the
closest multiple of 10 to the power minus *ndigits*; if two multiples are
@@ -1266,6 +1266,9 @@
negative). The return value is an integer if called with one argument,
otherwise of the same type as *number*.
+ For a general Python object ``number``, ``round(number, ndigits)`` delegates to
+ ``number.__round__(ndigits)``.
+
.. note::
The behavior of :func:`round` for floats can be surprising: for example,