Reference library
Files & data
Read and write files safely; parse JSON, CSV, and common text formats.
Build a Command-Line To-Do List Application with Data Persistence in Python
A persistent command-line to-do list that saves tasks as JSON, supporting add, show, toggle done, and quit commands.
import json
import os
TODO_FILE = "todos.json"
def load_todos():
if not os.path.exists(TODO_FILE):
return []
with open(TODO_FILE, "r") as f:
return json.load(f)
def save_todos(todos):
with open(TODO_FILE, "w") as f:
json.dump(todos, f, indent=2)
def show_todos(todos):
if not…Create a Personal Knowledge Base That Searches Notes Instantly in Python
Build a lightweight personal knowledge base with JSON storage and instant case-insensitive full-text search across note titles and content.
import json
import re
import sys
class PersonalKnowledgeBase:
def __init__(self, file_path="kb_notes.json"):
self.file_path = file_path
self.notes = self._load_notes()
def _load_notes(self):
try:
with open(self.file_path, "r") as f:
return json.load(f)
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Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.