XARGS_CMD = ("ls ./shards/ | "
             "xargs -n 1 -P {} -I{} "
             "python3 bert/create_pretraining_data.py "
             "--input_file=./shards/{} "
             "--output_file={}/{}.tfrecord "
             "--vocab_file={} "
             "--do_lower_case={} "
             "--max_predictions_per_seq={} "
             "--max_seq_length={} "
             "--masked_lm_prob={} "
             "--random_seed=34 "
             "--dupe_factor=5")

XARGS_CMD = XARGS_CMD.format(PROCESSES, '{}', '{}', PRETRAINING_DIR, '{}',
                             VOC_FNAME, DO_LOWER_CASE,
                             MAX_PREDICTIONS, MAX_SEQ_LENGTH, MASKED_LM_PROB)

tf.gfile.MkDir(PRETRAINING_DIR)
!$XARGS_CMD