Eryk Sun <eryk...@gmail.com> added the comment:
> IsADirectoryError: [Errno 21] Is a directory: 'not_a_dir/' The trailing slash forces the OS to handle "not_a_dir" as a directory [1]. A pathname that contains at least one non- <slash> character and that ends with one or more trailing <slash> characters shall not be resolved successfully unless the last pathname component before the trailing <slash> characters names an existing directory or a directory entry that is to be created for a directory immediately after the pathname is resolved. Mode "w" corresponds to low-level POSIX open() flags O_CREAT | O_TRUNC | O_WRONLY. If write access is requested for a directory, the open() system call must fail with EISDIR [2]. [EISDIR] The named file is a directory and oflag includes O_WRONLY or O_RDWR, or includes O_CREAT without O_DIRECTORY. In most cases, opening a directory with O_CREAT also fails with E_ISDIR. POSIX does permit an implementation to create a directory with O_CREAT | O_DIRECTORY. In Linux, however, O_CREAT always creates a regular file, regardless of O_DIRECTORY, so open(pathname, O_CREAT | flags) always fails with EISDIR when pathname is an existing directory or names a directory by way of a trailing slash. --- [1] https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13 [2] https://pubs.opengroup.org/onlinepubs/9699919799/functions/open.html ---------- nosy: +eryksun _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue43219> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com