gh-134449: fix grammar for `precision_with_grouping` in format description (#134608)

This amends commit f39a07be47cd9219eaf0e538ae32ad8239c88e66.

diff --git a/Doc/library/string.rst b/Doc/library/string.rst
index c4012483a52f730a63980a71ea370134b947db0c..23e157800754353c7d75e1e1ebb8b454c64c0f7d 100644 (file)
--- a/Doc/library/string.rst
+++ b/Doc/library/string.rst
@@ -328,7 +328,7 @@ The general form of a *standard format specifier* is:
    sign: "+" | "-" | " "
    width_and_precision: [`width_with_grouping`][`precision_with_grouping`]
    width_with_grouping: [`width`][`grouping`]
-   precision_with_grouping: "." [`precision`][`grouping`]
+   precision_with_grouping: "." [`precision`][`grouping`] | "." `grouping`
    width: `~python-grammar:digit`+
    precision: `~python-grammar:digit`+
    grouping: "," | "_"