add option to zipfile.writestr to open permissions

Lib/test/test_zipfile.py

@@ -318,6 +318,14 @@ class AbstractTestsWithSourceFile:
         self.assertEqual(b_info.compress_type, self.compression)
         self.assertEqual(b_info._compresslevel, 2)
 
+    def test_writestr_permission(self):
+        zipfp = zipfile.ZipFile(TESTFN2, "w")
+        zipfp.writestr("b.txt", "hello world", file_perm=0o755)
+        b_info = zipfp.getinfo('b.txt')
+        perm = oct(b_info.external_attr >> 16)
+        assert perm == '0o755'
+
+
     def test_read_return_size(self):
         # Issue #9837: ZipExtFile.read() shouldn't return more bytes
         # than requested.

Lib/zipfile.py

@@ -1751,12 +1751,14 @@ class ZipFile:
                 shutil.copyfileobj(src, dest, 1024*8)
 
     def writestr(self, zinfo_or_arcname, data,
-                 compress_type=None, compresslevel=None):
+                 compress_type=None, compresslevel=None,
+                 file_perm=0o600):
         """Write a file into the archive.  The contents is 'data', which
         may be either a 'str' or a 'bytes' instance; if it is a 'str',
         it is encoded as UTF-8 first.
         'zinfo_or_arcname' is either a ZipInfo instance or
-        the name of the file in the archive."""
+        the name of the file in the archive. Default permission is set to 600
+        (rw-------) but can be specified with file_perm."""
         if isinstance(data, str):
             data = data.encode("utf-8")
         if not isinstance(zinfo_or_arcname, ZipInfo):
@@ -1768,7 +1770,7 @@ class ZipFile:
                 zinfo.external_attr = 0o40775 << 16   # drwxrwxr-x
                 zinfo.external_attr |= 0x10           # MS-DOS directory flag
             else:
-                zinfo.external_attr = 0o600 << 16     # ?rw-------
+                zinfo.external_attr = file_perm << 16     # ?rw-------
         else:
             zinfo = zinfo_or_arcname