def _check_before_run(self):
    'Check if all files are available before going deeper'
    if (not osp.exists(self.dataset_dir)):
        raise RuntimeError("'{}' is not available".format(self.dataset_dir))
    if (not osp.exists(self.train_dir)):
        raise RuntimeError("'{}' is not available".format(self.train_dir))
    if (not osp.exists(self.query_dir)):
        raise RuntimeError("'{}' is not available".format(self.query_dir))
    if (not osp.exists(self.gallery_dir)):
        raise RuntimeError("'{}' is not available".format(self.gallery_dir))
Check if all files are available before going deeper
def _check_before_run(self):
    
    if (not osp.exists(self.dataset_dir)):
        raise RuntimeError("'{}' is not available".format(self.dataset_dir))
    if (not osp.exists(self.train_dir)):
        raise RuntimeError("'{}' is not available".format(self.train_dir))
    if (not osp.exists(self.query_dir)):
        raise RuntimeError("'{}' is not available".format(self.query_dir))
    if (not osp.exists(self.gallery_dir)):
        raise RuntimeError("'{}' is not available".format(self.gallery_dir))