def url(self, filename):
        base = self.config.base_url
        if base is None:
            return url_for('_uploads.uploaded_file', setname=self.name,
                           filename=filename, _external=True)
        else:
            return base + filename
This function gets the URL a file uploaded to this set would be
dataset/ETHPy150Open jeffwidman/flask-uploads/flask_uploads.py/UploadSet.url