Function TemporaryFile

Lib/tempfile.py:631–704

Create and return a temporary file. Arguments: 'prefix', 'suffix', 'dir' -- as for mkstemp. 'mode' -- the mode argument to io.open (default "w+b"). 'buffering' -- the buffer size argument to io.open (default -1). 'encoding' -- the encoding argument to io.open

(mode='w+b', buffering=-1, encoding=None,
                      newline=None, suffix=None, prefix=None,
                      dir=None, *, errors=None)

    _O_TMPFILE_WORKS = hasattr(_os, 'O_TMPFILE')

    def TemporaryFile(mode='w+b', buffering=-1, encoding=None,
                      newline=None, suffix=None, prefix=None,
                      dir=None, *, errors=None):
        """Create and return a temporary file.
        Arguments:
        'prefix', 'suffix', 'dir' -- as for mkstemp.
        'mode' -- the mode argument to io.open (default "w+b").
        'buffering' -- the buffer size argument to io.open (default -1).
        'encoding' -- the encoding argument to io.open (default None)
        'newline' -- the newline argument to io.open (default None)
        'errors' -- the errors argument to io.open (default None)
        The file is created as mkstemp() would do it.

        Returns an object with a file-like interface.  The file has no
        name, and will cease to exist when it is closed.
        """
        global _O_TMPFILE_WORKS

        if "b" not in mode:
            encoding = _io.text_encoding(encoding)

        prefix, suffix, dir, output_type = _sanitize_params(prefix, suffix, dir)

        flags = _bin_openflags
        if _O_TMPFILE_WORKS:
            fd = None
            def opener(*args):
                nonlocal fd
                flags2 = (flags | _os.O_TMPFILE) & ~_os.O_CREAT & ~_os.O_EXCL
                fd = _os.open(dir, flags2, 0o600)
                return fd
            try:
                file = _io.open(dir, mode, buffering=buffering,
                                newline=newline, encoding=encoding,
                                errors=errors, opener=opener)
                raw = getattr(file, 'buffer', file)
                raw = getattr(raw, 'raw', raw)
                raw.name = fd
                return file
            except IsADirectoryError:
                # Linux kernel older than 3.11 ignores the O_TMPFILE flag:
                # O_TMPFILE is read as O_DIRECTORY. Trying to open a directory
                # with O_RDWR|O_DIRECTORY fails with IsADirectoryError, a
                # directory cannot be open to write. Set flag to False to not
                # try again.
                _O_TMPFILE_WORKS = False
            except OSError:
                # The filesystem of the directory does not support O_TMPFILE.
                # For example, OSError(95, 'Operation not supported').
                #
                # On Linux kernel older than 3.11, trying to open a regular
                # file (or a symbolic link to a regular file) with O_TMPFILE
                # fails with NotADirectoryError, because O_TMPFILE is read as
                # O_DIRECTORY.
                pass
            # Fallback to _mkstemp_inner().

        fd = None