编程打卡：面向对象程序设计

import os
import sqlite3

# Create a database connection
conn = sqlite3.connect('todo.db')

# Create a todo table
cur = conn.cursor()
cur.execute('''
CREATE TABLE todo (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  title TEXT NOT NULL,
  due_date DATETIME NOT NULL,
  completed BOOLEAN NOT NULL DEFAULT FALSE
)
''')

# Insert some sample data
cur.execute('''
INSERT INTO todo (title, due_date) VALUES
('Buy groceries', '2023-05-25'),
('Clean the house', '2023-05-26'),
('Do the laundry', '2023-05-27')
''')

# Commit the changes to the database
conn.commit()

# Close the database connection
conn.close()

# Define a function to get all todos
def get_todos():
  conn = sqlite3.connect('todo.db')
  cur = conn.cursor()
  cur.execute('SELECT * FROM todo')
  todos = cur.fetchall()
  conn.close()
  return todos

# Define a function to add a todo
def add_todo(title, due_date):
  conn = sqlite3.connect('todo.db')
  cur = conn.cursor()
  cur.execute('INSERT INTO todo (title, due_date) VALUES (?, ?)', (title, due_date))
  conn.commit()
  conn.close()

# Define a function to delete a todo
def delete_todo(id):
  conn = sqlite3.connect('todo.db')
  cur = conn.cursor()
  cur.execute('DELETE FROM todo WHERE id = ?', (id,))
  conn.commit()
  conn.close()

# Define a function to mark a todo as completed
def mark_todo_completed(id):
  conn = sqlite3.connect('todo.db')
  cur = conn.cursor()
  cur.execute('UPDATE todo SET completed = 1 WHERE id = ?', (id,))
  conn.commit()
  conn.close()

# Define a function to get the number of todos
def get_number_of_todos():
  conn = sqlite3.connect('todo.db')
  cur = conn.cursor()
  cur.execute('SELECT COUNT(*) FROM todo')
  number_of_todos = cur.fetchone()[0]
  conn.close()
  return number_of_todos

# Define a function to get the number of completed todos
def get_number_of_completed_todos():
  conn = sqlite3.connect('todo.db')
  cur = conn.cursor()
  cur.execute('SELECT COUNT(*) FROM todo WHERE completed = 1')
  number_of_completed_todos = cur.fetchone()[0]
  conn.close()
  return number_of_completed_todos

# Define a function to get the number of incomplete todos
def get_number_of_incomplete_todos():
  return get_number_of_todos() - get_number_of_completed_todos()