写一个办公工具的实现可以基于Python语言和相应的第三方库创建。下面是一个基本的“待办事项”命令行办公工具的示例，它可以简单处理添加、列出和完成待办事项：
```python
import argparse
parser = argparse.ArgumentParser(description='A simple to-do list CLI tool')
subparsers = parser.add_subparsers(dest='command', help='sub-command help')
# Add Sub-Command Parser
add_parser = subparsers.add_parser('add', help='add a task to the list')
add_parser.add_argument('task', type=str, help='the task description')
# List Sub-Command Parser
list_parser = subparsers.add_parser('list', help='list all tasks in the to-do list')
# Complete Sub-Command Parser
complete_parser = subparsers.add_parser('complete', help='mark a task as completed')
complete_parser.add_argument('task_index', type=int, help='the index of the completed task')
# Parse Arguments
args = parser.parse_args()
if args.command == 'add':
with open('todo.txt', 'a') as f:
f.write(args.task + '\n')
print('Task added successfully.')
elif args.command == 'list':
with open('todo.txt', 'r') as f:
tasks = f.readlines()
if len(tasks) == 0:
print('No tasks found.')
else:
for i, task in enumerate(tasks):
print(f'[{i}] {task}', end='')
elif args.command == 'complete':
with open('todo.txt', 'r') as f:
tasks = f.readlines()
if len(tasks) <= args.task_index:
print('Invalid task index.')
else:
tasks[args.task_index] = tasks[args.task_index].replace('\n', ' ✓\n')
with open('todo.txt', 'w') as f:
f.writelines(tasks)
print('Task marked as completed successfully.')
```
该命令行工具基于argparse库实现，该库可以帮助为命令行界面指定参数、子命令等。该示例中将待办事项存储在名为“todo.txt”的文本文件中，完成的任务以特殊符号“✓”标记。对于更复杂的工具，可能需要使用其他Python库和框架来实现相应的功能。
