New submission from Bart Robinson <b...@bartrobinson.com>:
When a ZipFile object is created with mode='a', the existing file contents are checked for the magic number b"PK\005\006" near the end of the file. If a non-zipfile just happens to contain this magic number, it can confuse the library into assuming the file is a zipfile when it is not. It would be great if ZipFile.__init__() provided a way to skip the magic-number check and force a new central directory to be appended to the file. This could take the form of an additional named argument like ZipFile.__init__(force_append=True), or an additional character in the mode string, like 'a+'. Either of these options should be backward-compatible with existing code. Currently, my company has code that uses monkey-patching to work around the lack of this feature in the standard library. We use mode='a' to append metadata to files in existing formats that can contain arbitrary binary data and so occasionally include the magic number. ---------- components: Library (Lib) messages: 382691 nosy: Bart Robinson priority: normal severity: normal status: open title: Provide a way to skip magic-number search in ZipFile(mode='a') type: enhancement versions: Python 3.10 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue42594> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
