From 4ce0e4d331c34ea1fb8b7f7ec50a0036f3ddcab3 Mon Sep 17 00:00:00 2001
From: doe1080 <98906116+doe1080@users.noreply.github.com>
Date: Wed, 19 Aug 2026 12:55:26 +0900
Subject: [PATCH] [utils] Deprecate `number_of_digits` (#17300)

Authored by: doe1080
---
 pyproject.toml              | 1 +
 yt_dlp/YoutubeDL.py         | 5 ++---
 yt_dlp/utils/_deprecated.py | 4 ++++
 yt_dlp/utils/_utils.py      | 4 ----
 4 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index d53cd80235..125e969c4f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -396,6 +396,7 @@ banned-from = [
 "yt_dlp.utils.intlist_to_bytes".msg = "Use `bytes` instead."
 "yt_dlp.utils.jwt_encode_hs256".msg = "Use `yt_dlp.utils.jwt_encode` instead."
 "yt_dlp.utils.make_dir".msg = "Use `yt_dlp.utils.make_parent_dirs` instead."
+"yt_dlp.utils.number_of_digits".msg = "Do not use"
 "yt_dlp.utils.decodeArgument".msg = "Do not use"
 "yt_dlp.utils.decodeFilename".msg = "Do not use"
 "yt_dlp.utils.encodeFilename".msg = "Do not use"
diff --git a/yt_dlp/YoutubeDL.py b/yt_dlp/YoutubeDL.py
index a2675bd44d..051d1b0fb4 100644
--- a/yt_dlp/YoutubeDL.py
+++ b/yt_dlp/YoutubeDL.py
@@ -140,7 +140,6 @@ from .utils import (
     locked_file,
     make_archive_id,
     make_parent_dirs,
-    number_of_digits,
     orderedSet,
     orderedSet_from_options,
     parse_filesize,
@@ -1286,8 +1285,8 @@ class YoutubeDL:
         # For fields playlist_index, playlist_autonumber and autonumber convert all occurrences
         # of %(field)s to %(field)0Nd for backward compatibility
         field_size_compat_map = {
-            'playlist_index': number_of_digits(info_dict.get('__last_playlist_index') or 0),
-            'playlist_autonumber': number_of_digits(info_dict.get('n_entries') or 0),
+            'playlist_index': len(str(info_dict.get('__last_playlist_index') or 0)),
+            'playlist_autonumber': len(str(info_dict.get('n_entries') or 0)),
             'autonumber': self.params.get('autonumber_size') or 5,
         }
 
diff --git a/yt_dlp/utils/_deprecated.py b/yt_dlp/utils/_deprecated.py
index 9fada27fd8..3f8aea1b20 100644
--- a/yt_dlp/utils/_deprecated.py
+++ b/yt_dlp/utils/_deprecated.py
@@ -58,4 +58,8 @@ def make_dir(path, to_screen=None):
         return False
 
 
+def number_of_digits(number):
+    return len('%d' % number)
+
+
 compiled_regex_type = type(re.compile(''))
diff --git a/yt_dlp/utils/_utils.py b/yt_dlp/utils/_utils.py
index a6e0baffcd..526d1ab9eb 100644
--- a/yt_dlp/utils/_utils.py
+++ b/yt_dlp/utils/_utils.py
@@ -4864,10 +4864,6 @@ def remove_terminal_sequences(string):
     return _terminal_sequences_re.sub('', string)
 
 
-def number_of_digits(number):
-    return len('%d' % number)
-
-
 def join_nonempty(*values, delim='-', from_dict=None):
     if from_dict is not None:
         values = (traversal.traverse_obj(from_dict, variadic(v)) for v in values)