def _get_p_number(self, base_path, base_dir):
        if base_path and base_dir.startswith(base_path):
            return base_path.count('/') + 1
        else:
            return -1
Return the appropriate value for the -p argument to patch.
dataset/ETHPy150Open reviewboard/rbtools/rbtools/clients/__init__.py/SCMClient._get_p_number