exiftool.py 文件源码

def execute(self, *params):
        """Execute the given batch of parameters with ``exiftool``.

        This method accepts any number of parameters and sends them to
        the attached ``exiftool`` process.  The process must be
        running, otherwise ``ValueError`` is raised.  The final
        ``-execute`` necessary to actually run the batch is appended
        automatically; see the documentation of :py:meth:`start()` for
        the common options.  The ``exiftool`` output is read up to the
        end-of-output sentinel and returned as a raw ``bytes`` object,
        excluding the sentinel.

        The parameters must also be raw ``bytes``, in whatever
        encoding exiftool accepts.  For filenames, this should be the
        system's filesystem encoding.

        .. note:: This is considered a low-level method, and should
           rarely be needed by application developers.
        """
        if not self.running:
            raise ValueError("ExifTool instance not running.")
        self._process.stdin.write(b"\n".join(params + (b"-execute\n",)))
        self._process.stdin.flush()
        output = b""
        fd = self._process.stdout.fileno()
        while not output[-32:].strip().endswith(sentinel):
            output += os.read(fd, block_size)
        return output.strip()[:-len(sentinel)]