gh-155039: Support copy.replace() for zipfile.ZipInfo

Doc/library/zipfile.rst

@@ -1041,6 +1041,13 @@ Instances have the following methods and attributes:
    Size of the uncompressed file.
 
 
+:class:`ZipInfo` objects support :func:`copy.replace`,
+which returns a copy of the object with the specified attributes replaced.
+
+.. versionchanged:: next
+   Added support for :func:`copy.replace`.
+
+
 .. _zipfile-commandline:
 .. program:: zipfile
 

Lib/test/test_zipfile/test_core.py

@@ -1,6 +1,7 @@
 import _pyio
 import array
 import contextlib
+import copy
 import errno
 import importlib.util
 import io
@@ -5566,6 +5567,42 @@ def test_compresslevel_property(self):
         self.assertEqual(zinfo.compress_level, 8)
         self.assertEqual(zinfo._compresslevel, 8)
 
+    def test_replace(self):
+        zinfo = zipfile.ZipInfo('name.txt', (2020, 1, 2, 3, 4, 5))
+        zinfo.file_size = 100
+        zinfo.CRC = 42
+        new = copy.replace(zinfo, filename='other.txt',
+                           compress_type=zipfile.ZIP_DEFLATED)
+        self.assertIsInstance(new, zipfile.ZipInfo)
+        self.assertEqual(new.filename, 'other.txt')
+        self.assertEqual(new.orig_filename, 'other.txt')
+        self.assertEqual(new.compress_type, zipfile.ZIP_DEFLATED)
+        # Not replaced attributes are inherited from the original object.
+        self.assertEqual(new.date_time, (2020, 1, 2, 3, 4, 5))
+        self.assertEqual(new.file_size, 100)
+        self.assertEqual(new.CRC, 42)
+        # The original object is left unchanged.
+        self.assertEqual(zinfo.filename, 'name.txt')
+        self.assertEqual(zinfo.compress_type, zipfile.ZIP_STORED)
+
+        new = copy.replace(zinfo, date_time=(1980, 1, 1, 0, 0, 0))
+        self.assertEqual(new.date_time, (1980, 1, 1, 0, 0, 0))
+        with self.assertRaises(ValueError):
+            copy.replace(zinfo, date_time=(1979, 12, 31, 0, 0, 0))
+        with self.assertRaisesRegex(TypeError, "'filenam'"):
+            copy.replace(zinfo, filenam='other.txt')
+        with self.assertRaisesRegex(TypeError, "'orig_filename'"):
+            copy.replace(zinfo, orig_filename='other.txt')
+
+    def test_replace_unset_attributes(self):
+        # header_offset and CRC are only set when the object is written
+        # to or read from an archive.
+        zinfo = zipfile.ZipInfo('name.txt')
+        new = copy.replace(zinfo, file_size=5)
+        self.assertEqual(new.file_size, 5)
+        self.assertFalse(hasattr(new, 'header_offset'))
+        self.assertFalse(hasattr(new, 'CRC'))
+
 
 class CommandLineTest(unittest.TestCase):
 

Lib/zipfile/__init__.py

@@ -4,6 +4,7 @@
 XXX references to utf-8 need further investigation.
 """
 import binascii
+import copy
 import io
 import os
 import shutil
@@ -501,6 +502,22 @@ def _compresslevel(self):
     def _compresslevel(self, value):
         self.compress_level = value
 
+    def __replace__(self, /, **changes):
+        unexpected = changes.keys() - _zipinfo_attributes
+        if unexpected:
+            raise TypeError(f'__replace__() got an unexpected keyword '
+                            f'argument {min(unexpected)!r}')
+        new = copy.copy(self)
+        if 'filename' in changes:
+            filename = changes.pop('filename')
+            new.orig_filename = filename
+            new.filename = _sanitize_filename(filename)
+        if changes.get('date_time', (1980,))[0] < 1980:
+            raise ValueError('ZIP does not support timestamps before 1980')
+        for name, value in changes.items():
+            setattr(new, name, value)
+        return new
+
     def __repr__(self):
         result = ['<%s filename=%r' % (self.__class__.__name__, self.filename)]
         if self.compress_type != ZIP_STORED:
@@ -705,6 +722,11 @@ def is_dir(self):
         return False
 
 
+# Attributes which can be replaced by ZipInfo.__replace__().
+_zipinfo_attributes = frozenset(ZipInfo.__slots__) - {
+    'orig_filename', '_raw_time', '_end_offset'}
+
+
 # ZIP encryption uses the CRC32 one-byte primitive for scrambling some
 # internal keys. We noticed that a direct implementation is faster than
 # relying on binascii.crc32().

Misc/NEWS.d/next/Library/2026-08-01-19-00-00.gh-issue-155039.Zp1nFo.rst

@@ -0,0 +1 @@
+:class:`zipfile.ZipInfo` objects now support :func:`copy.replace`.