使用子进程检查文件中的记录数

import subprocess

def count_records(filename):
    # 创建子进程并执行命令
    result = subprocess.run(['wc', '-l', filename], capture_output=True, text=True)
    
    # 检查命令执行结果
    if result.returncode == 0:
        # 提取记录数
        record_count = int(result.stdout.strip().split()[0])
        return record_count
    else:
        # 命令执行失败
        return -1

# 调用函数并打印结果
filename = 'data.txt'
record_count = count_records(filename)
print(f"The file '{filename}' contains {record_count} records.")