From caefd01d0397b1171ebad3ecca600ab5da5ac06e Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Fri, 28 Feb 2025 05:07:49 +0300
Subject: [PATCH 1/4] gh-130662: make Fraction's formatting more compatible wrt
 float's

---
 Lib/fractions.py           | 4 ++--
 Lib/test/test_fractions.py | 8 ++------
 2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/Lib/fractions.py b/Lib/fractions.py
index f0cbc8c2e6c012..d25935f7602842 100644
--- a/Lib/fractions.py
+++ b/Lib/fractions.py
@@ -168,9 +168,9 @@ def _round_to_figures(n, d, figures):
     # A '0' that's *not* followed by another digit is parsed as a minimum width
     # rather than a zeropad flag.
     (?P<zeropad>0(?=[0-9]))?
-    (?P<minimumwidth>0|[1-9][0-9]*)?
+    (?P<minimumwidth>[0-9]+)?
     (?P<thousands_sep>[,_])?
-    (?:\.(?P<precision>0|[1-9][0-9]*))?
+    (?:\.(?P<precision>[0-9]+))?
     (?P<presentation_type>[eEfFgG%])
 """, re.DOTALL | re.VERBOSE).fullmatch
 
diff --git a/Lib/test/test_fractions.py b/Lib/test/test_fractions.py
index 98dccbec9566ac..e3a8f7c8d61aac 100644
--- a/Lib/test/test_fractions.py
+++ b/Lib/test/test_fractions.py
@@ -1530,6 +1530,8 @@ def test_format_f_presentation_type(self):
             (F(51, 1000), '.1f', '0.1'),
             (F(149, 1000), '.1f', '0.1'),
             (F(151, 1000), '.1f', '0.2'),
+            (F(1, 3), '.016f', '0.3333333333333333'),  # issue gh-130662
+            (F(1, 3), '0030.016f', '0000000000000.3333333333333333'),
         ]
         for fraction, spec, expected in testcases:
             with self.subTest(fraction=fraction, spec=spec):
@@ -1628,12 +1630,6 @@ def test_invalid_formats(self):
             '=010%',
             '>00.2f',
             '>00f',
-            # Too many zeros - minimum width should not have leading zeros
-            '006f',
-            # Leading zeros in precision
-            '.010f',
-            '.02f',
-            '.000f',
             # Missing precision
             '.e',
             '.f',

From 9425ff2e8381241b092f037349b37d630e837721 Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Sat, 1 Mar 2025 04:04:20 +0300
Subject: [PATCH 2/4] Update Lib/test/test_fractions.py

---
 Lib/test/test_fractions.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Lib/test/test_fractions.py b/Lib/test/test_fractions.py
index e3a8f7c8d61aac..6a0ec74750ef13 100644
--- a/Lib/test/test_fractions.py
+++ b/Lib/test/test_fractions.py
@@ -1530,8 +1530,8 @@ def test_format_f_presentation_type(self):
             (F(51, 1000), '.1f', '0.1'),
             (F(149, 1000), '.1f', '0.1'),
             (F(151, 1000), '.1f', '0.2'),
-            (F(1, 3), '.016f', '0.3333333333333333'),  # issue gh-130662
-            (F(1, 3), '0030.016f', '0000000000000.3333333333333333'),
+            (F(22, 7), '.02f', '3.14'),  # issue gh-130662
+            (F(22, 7), '005.02f', '03.14'),
         ]
         for fraction, spec, expected in testcases:
             with self.subTest(fraction=fraction, spec=spec):

From e0d2526a1ba8a16841e917b29094a8dd719b5b3d Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Mon, 2 Jun 2025 14:28:40 +0300
Subject: [PATCH 3/4] address review: add news

---
 .../Library/2025-06-02-14-28-30.gh-issue-130662.EIgIR8.rst     | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Library/2025-06-02-14-28-30.gh-issue-130662.EIgIR8.rst

diff --git a/Misc/NEWS.d/next/Library/2025-06-02-14-28-30.gh-issue-130662.EIgIR8.rst b/Misc/NEWS.d/next/Library/2025-06-02-14-28-30.gh-issue-130662.EIgIR8.rst
new file mode 100644
index 00000000000000..9d541eef7d647a
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-06-02-14-28-30.gh-issue-130662.EIgIR8.rst
@@ -0,0 +1,3 @@
+Accept leading zeros in precision/width fields for
+:class:`~fractions.Fraction` formatting, for example ``format(Fraction(1,
+3), '.016f')``.

From a54c7e57c5dbc411b27d2f2ca21a062e3fc49f43 Mon Sep 17 00:00:00 2001
From: Sergey B Kirpichev <skirpichev@gmail.com>
Date: Mon, 2 Jun 2025 14:55:03 +0300
Subject: [PATCH 4/4] Apply suggestions from code review
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
---
 .../next/Library/2025-06-02-14-28-30.gh-issue-130662.EIgIR8.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Misc/NEWS.d/next/Library/2025-06-02-14-28-30.gh-issue-130662.EIgIR8.rst b/Misc/NEWS.d/next/Library/2025-06-02-14-28-30.gh-issue-130662.EIgIR8.rst
index 9d541eef7d647a..e07200f9a3fbbd 100644
--- a/Misc/NEWS.d/next/Library/2025-06-02-14-28-30.gh-issue-130662.EIgIR8.rst
+++ b/Misc/NEWS.d/next/Library/2025-06-02-14-28-30.gh-issue-130662.EIgIR8.rst
@@ -1,3 +1,3 @@
-Accept leading zeros in precision/width fields for
+Accept leading zeros in precision and width fields for
 :class:`~fractions.Fraction` formatting, for example ``format(Fraction(1,
 3), '.016f')``.