请将下列shell语句转换为python语句：if [ ${stage} -le 4 ] && [ ${stop_stage} -ge 4 ]; then echo "Prepare data, prepare requried format" # For wav feature, just copy the data. mfcc/fbank extraction is done in training for x in ${train_set} ${train_dev} ${recog_set}; do if [ $data_type == "shard" ]; then tools/make_shard_list.py --num_utts_per_shard $num_utts_per_shard \ --num_threads 16 data/$x/wav.scp data/$x/text \ $(realpath data/$x/shards) data/$x/data.list else tools/make_raw_list.py data/$x/wav.scp data/$x/text \ data/$x/data.list fi done fi

import os

if stage <= 4 and stop_stage >= 4:
    print("Prepare data, prepare required format")
    for x in [train_set, train_dev, recog_set]:
        if data_type == "shard":
            os.system(f"tools/make_shard_list.py --num_utts_per_shard {num_utts_per_shard} --num_threads 16 data/{x}/wav.scp data/{x}/text $(realpath data/{x}/shards) data/{x}/data.list")
        else:
            os.system(f"tools/make_raw_list.py data/{x}/wav.scp data/{x}/text data/{x}/data.list")

注意：在 Python 中，使用 os.system() 函数来执行 shell 命令。在这个例子中，我们使用了 f-string 来将变量插入到 shell 命令中。由于变量名中带有下划线，因此需要将其转换为 Python 语法中的下划线。