My Project 2: Building a Simple Memo App with Python + Streamlit

Source: Dev.to

Project Overview

The memo app lets you:

• Add a new memo
• Store it in a memos.json file
• View all saved memos

It can be used either from the console or through a Streamlit web UI, demonstrating file handling, JSON storage, and UI transformation.

Project Structure

memo_app/
│
├── memo_app.py               # Console version
├── memo_app_streamlit.py     # Streamlit version
└── memos.json                # Memo storage file

Console Version (memo_app.py)

Code

import json
import os
from datetime import datetime

now = datetime.now().strftime("%Y-%m-%d")
FILE_NAME = "memos.json"

# Ensure the storage file exists
if not os.path.exists(FILE_NAME):
    with open(FILE_NAME, "w") as f:
        json.dump([], f)

def load_memos():
    with open(FILE_NAME, "r") as f:
        return json.load(f)

def save_memos(memos):
    with open(FILE_NAME, "w") as f:
        json.dump(memos, f, indent=2)

print("=== Sabin's Memo App ===")
print("1) Add Memo")
print("2) Show Memos")

choice = input("Select option: ")

if choice == "1":
    memo = input("Write memo: ")
    memos = load_memos()
    memos.append({"text": memo, "date": now})
    save_memos(memos)
    print("Memo saved!")

elif choice == "2":
    memos = load_memos()
    print("=== Memo List ===")
    for i, m in enumerate(memos, start=1):
        print(f"{i}. {m['text']}  ({m['date']})")

else:
    print("Invalid option.")

Streamlit Version (memo_app_streamlit.py)

Code

import streamlit as st
import json
import os
from datetime import datetime

FILE_NAME = "memos.json"

# Ensure the storage file exists
if not os.path.exists(FILE_NAME):
    with open(FILE_NAME, "w") as f:
        json.dump([], f)

def load_memos():
    with open(FILE_NAME, "r") as f:
        return json.load(f)

def save_memos(memos):
    with open(FILE_NAME, "w") as f:
        json.dump(memos, f, indent=2)

st.title("📝 Sabin's Memo App (Streamlit Version)")

menu = st.radio("Select an option:", ["Add Memo", "Show Memos"])

if menu == "Add Memo":
    text = st.text_input("Write your memo:")

    if st.button("Save Memo"):
        if text.strip() == "":
            st.warning("Memo cannot be empty.")
        else:
            now = datetime.now().strftime("%Y-%m-%d")
            memos = load_memos()
            memos.append({"text": text, "date": now})
            save_memos(memos)
            st.success("Memo saved!")

elif menu == "Show Memos":
    memos = load_memos()
    if not memos:
        st.info("No memos yet.")
    else:
        st.subheader("📄 Memo List")
        for i, memo in enumerate(memos, start=1):
            st.write(f"**{i}. {memo['text']}**  ({memo['date']})")

How to Run

Console Version

python3 memo_app.py

Streamlit Version

pip install streamlit
streamlit run memo_app_streamlit.py

The Streamlit command will launch the web UI in your default browser.

What I Learned

• Storing data with JSON files
• Safe read/write of local storage
• Adding a UI layer using Streamlit
• Converting a CLI tool into a web app
• The value of small, focused projects for building solid foundations

Future Improvements

• Add memo deletion
• Add memo editing
• Switch storage to SQLite
• Implement search/filter functionality
• Provide a dark/light mode toggle in Streamlit