Python Weather App (CLI + Flask)

This starter pack includes:

• A CLI app (weather_cli.py) to get current weather by city.
• A Flask web app (weather_app.py) with a simple form.

1) Setup

# 1. Open a terminal in this folder
# 2. Create and activate a virtual environment (Windows)
python -m venv .venv
.venv\Scripts\activate

# macOS/Linux
# python3 -m venv .venv
# source .venv/bin/activate

# 3. Install dependencies
pip install -r requirements.txt

# 4. Add your API key
#   Copy .env.example to .env and paste your OpenWeather API key
#   You can get a free key by signing up at OpenWeather and creating an API key.
cp .env.example .env  # (Windows PowerShell: copy .env.example .env)

Edit .env to look like:

OPENWEATHER_API_KEY=YOUR_REAL_KEY

2) Run the CLI app

python weather_cli.py "Colombo"
# or
python weather_cli.py
# (then type the city when asked)

3) Run the Flask web app

# Option A
flask --app weather_app run --reload

# Option B
python weather_app.py  # runs with debug=True

Open your browser at http://127.0.0.1:5000/ and search for a city.

Notes

• Units are set to metric (°C). Change units param to imperial (°F) if you prefer.
• Common errors:
  • 401: Wrong or missing API key.
  • 404: City not found (check spelling).
  • 429: Too many requests on the free plan—wait and try again.