bpo-27772: Make preceding width with 0 valid in string format. (GH-11270)

Previously it was an error with confusing error message.

1 files changed, 6 insertions, 2 deletions

diff --git a/Doc/library/string.rst b/Doc/library/string.rst
index 54786d0c2ab..1bfd518349b 100644
--- a/Doc/library/string.rst
+++ b/Doc/library/string.rst
@@ -347,8 +347,8 @@ The meaning of the various alignment options is as follows:
    | ``'='`` | Forces the padding to be placed after the sign (if any)  |
    |         | but before the digits.  This is used for printing fields |
    |         | in the form '+000000120'. This alignment option is only  |
-   |         | valid for numeric types.  It becomes the default when '0'|
-   |         | immediately precedes the field width.                    |
+   |         | valid for numeric types.  It becomes the default for     |
+   |         | numbers when '0' immediately precedes the field width.   |
    +---------+----------------------------------------------------------+
    | ``'^'`` | Forces the field to be centered within the available     |
    |         | space.                                                   |
@@ -424,6 +424,10 @@ When no explicit alignment is given, preceding the *width* field by a zero
 sign-aware zero-padding for numeric types.  This is equivalent to a *fill*
 character of ``'0'`` with an *alignment* type of ``'='``.
 
+.. versionchanged:: 3.10
+   Preceding the *width* field by ``'0'`` no longer affects the default
+   alignment for strings.
+
 The *precision* is a decimal number indicating how many digits should be
 displayed after the decimal point for a floating point value formatted with
 ``'f'`` and ``'F'``, or before and after the decimal point for a floating point