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Documentation Index

Fetch the complete documentation index at: https://todocli.vmslab.work/llms.txt

Use this file to discover all available pages before exploring further.

This page contains the business logic for the Todo CLI application.
All core operations like adding, listing, marking, and clearing tasks are defined here.

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Storage

  • Tasks are stored in a file: todo_data.json
  • The format is JSON, with a list of objects:
JSON
[
  {
    "id": 1,
    "text": "Buy milk",
    "done": false,
    "priority": "medium",
    "created": "2025-06-01T10:00:00+00:00",
    "due": "2025-06-10",
    "tags": ["shopping", "errands"]
  }
]

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Task structure

Each task is defined using a TypedDict for type safety and readability:
Python
class TaskDict(TypedDict):
  id: int
  text: str
  done: bool
  priority: Literal["low", "medium", "high"]
  created: str
  due: Optional[str]
  tags: Optional[list[str]]
  • The default priority for new tasks is “medium”.
  • The created field is always generated automatically.
  • The due field is optional and can be left blank.

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Function summary

FunctionDescription
load_tasks()Load tasks from the JSON file
save_tasks(tasks)Save tasks to the JSON file
add_task(text)Add a new task with optional priority and due date
list_tasks()Return all existing tasks
complete_task(id)Mark a task as completed by ID
delete_task(id)Delete a task by ID
edit_task(...)Edit an existing task’s text, priority, due date or tags
clear_tasks()Remove all tasks from the list

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File organization

To make the code more maintainable, functions in core.py are grouped by responsibility.
SectionResponsibilityFunctions
🔄 File operationsLoad and save task data in JSON formatload_tasks, save_tasks
➕ Task creationAdd new tasks with automatic ID and statusadd_task
📄 Task readingRead and return task datalist_tasks
✅ Task updatesModify the status of taskscomplete_task
✅ Task editModify the status or content of taskscomplete_task, edit_task
❌ Task deletionRemove tasks individually or all at oncedelete_task, clear_tasks

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Notes

  • Task IDs are incremented automatically.
  • If the storage file is missing or invalid, an empty list is returned.
  • All tasks are stored in JSON with indent=2 and ensure_ascii=False.
  • The design is modular and easy to extend to:
    • Tags or categories
    • Date reminders or recurring tasks
    • Database or cloud backends