Pending removal in Python 3.19

• ctypes:

  • Implicitly switching to the MSVC-compatible struct layout by setting _pack_ but not _layout_ on non-Windows platforms.

• hashlib:

  • In hash function constructors such as new() or the direct hash-named constructors such as md5() and sha256(), their optional initial data parameter could also be passed a keyword argument named data= or string= in various hashlib implementations.

    Support for the string keyword argument name is now deprecated and slated for removal in Python 3.19.

    Before Python 3.13, the string keyword parameter was not correctly supported depending on the backend implementation of hash functions. Prefer passing the initial data as a positional argument for maximum backwards compatibility.

• http.cookies:

  • http.cookies.Morsel.js_output() is deprecated and will be removed in Python 3.19.

  • http.cookies.BaseCookie.js_output() is deprecated and will be removed in Python 3.19.

• imaplib:

  • Altering IMAP4.file is now deprecated and slated for removal in Python 3.19. This property is now unused and changing its value does not automatically close the current file.

    Before Python 3.14, this property was used to implement the corresponding read() and readline() methods for IMAP4 but this is no longer the case since then.