__init__.py 文件源码

def show(self, delete_after=20, scale=10, border=None, color='#000',
             background='#fff'):  # pragma: no cover
        """\
        Displays this QR code.

        This method is mainly intended for debugging purposes.

        This method saves the output of the :py:meth:`png` method (by default
        with a scaling factor of 10) to a temporary file and opens it with the
        standard PNG viewer application or within the standard webbrowser.
        The temporary file is deleted afterwards (unless `delete_after` is set
        to ``None``).

        If this method does not show any result, try to increase the
        `delete_after` value or set it to ``None``

        :param delete_after: Time in seconds to wait till the temporary file is
                deleted.
        """
        import os
        import time
        import tempfile
        import webbrowser
        import threading
        try:  # Python 2
            from urlparse import urljoin
            from urllib import pathname2url
        except ImportError:  # Python 3
            from urllib.parse import urljoin
            from urllib.request import pathname2url

        def delete_file(name):
            time.sleep(delete_after)
            try:
                os.unlink(name)
            except OSError:
                pass

        f = tempfile.NamedTemporaryFile('wb', suffix='.png', delete=False)
        try:
            self.save(f, scale=scale, color=color, background=background,
                      border=border)
        except:
            f.close()
            os.unlink(f.name)
            raise
        f.close()
        webbrowser.open_new_tab(urljoin('file:', pathname2url(f.name)))
        if delete_after is not None:
            t = threading.Thread(target=delete_file, args=(f.name,))
            t.start()