snzip · July 20, 2023 06:39 · May 15, 2022
diff --git a/mk_zip_patch.py b/mk_zip_patch.py
@@ -0,0 +1,82 @@
+import os
+import argparse
+import collections
+import tempfile
+import zipfile
+import filecmp
+import shutil
+import shlex
+
+ZipCmpResult = collections.namedtuple('ZipCmpResult',
+                                      ['to_rm', 'to_cmp', 'to_add'])
+
+
+def make_parser():
+    parser = argparse.ArgumentParser(
+        description='Make patch zip file from two similar zip files.')
+    parser.add_argument(
+        '--oldfile',
+        default=os.path.join('share', 'old.zip'),
+        help='default: %(default)s')
+    parser.add_argument(
+        '--newfile',
+        default=os.path.join('share', 'new.zip'),
+        help='default: %(default)s')
+    parser.add_argument(
+        '--toname',
+        default=os.path.join('share', 'patch'),
+        help='default: %(default)s')
+    return parser
+
+
+def zipcmp(old, new):
+    with zipfile.ZipFile(old) as zinfile:
+        old_names = set(zinfile.namelist())
+    with zipfile.ZipFile(new) as zinfile:
+        new_names = set(zinfile.namelist())
+    to_rm = old_names - new_names
+    to_cmp = old_names & new_names
+    to_add = new_names - old_names
+    return ZipCmpResult(to_rm, to_cmp, to_add)
+
+
+def compare_files(old, new, cmpresult):
+    with tempfile.TemporaryDirectory() as tmpdir, \
+         zipfile.ZipFile(old) as zinfile_old, \
+         zipfile.ZipFile(new) as zinfile_new:
+        old_dest = os.path.join(tmpdir, 'old')
+        new_dest = os.path.join(tmpdir, 'new')
+        os.mkdir(old_dest)
+        os.mkdir(new_dest)
+        for filename in cmpresult.to_cmp:
+            zinfile_old.extract(filename, path=old_dest)
+            zinfile_new.extract(filename, path=new_dest)
+            if not filecmp.cmp(
+                    os.path.join(old_dest, filename),
+                    os.path.join(new_dest, filename),
+                    shallow=False):
+                cmpresult.to_add.add(filename)
+
+
+def mkpatch(new, cmpresult, to_name):
+    with zipfile.ZipFile(new) as zinfile, \
+         zipfile.ZipFile(to_name + '.zip', 'w') as zoutfile:
+        for filename in cmpresult.to_add:
+            with zinfile.open(filename) as infile, \
+                 zoutfile.open(filename, 'w') as outfile:
+                shutil.copyfileobj(infile, outfile)
+    with open(to_name + '.sh', 'w', encoding='utf-8') as outfile:
+        outfile.write('#!/bin/sh\n')
+        for filename in cmpresult.to_rm:
+            outfile.write('rm {}\n'.format(shlex.quote(filename)))
+
+
+def main():
+    args = make_parser().parse_args()
+    cmpresult = zipcmp(args.oldfile, args.newfile)
+    compare_files(args.oldfile, args.newfile, cmpresult)
+    mkpatch(args.newfile, cmpresult, args.toname)
+
+
+if __name__ == '__main__':
+    main()