How do you deploy Python web applications to production? Python web applications को production में कैसे deploy करते हैं?

# Using Gunicorn (WSGI server)
# Install: pip install gunicorn
# Run: gunicorn -w 4 -b 0.0.0.0:8000 app:app
# or for Django: gunicorn myproject.wsgi:application

# Nginx configuration (reverse proxy)
server {
    listen 80;
    server_name example.com;
    
    location / {
        proxy_pass http://localhost:8000;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    }
}

# Supervisor (process manager)
[program:myapp]
command=gunicorn -w 4 -b 0.0.0.0:8000 app:app
directory=/home/user/myapp
autostart=true
autorestart=true

# Environment variables (.env)
DATABASE_URL=postgresql://user:password@localhost:5432/db
SECRET_KEY=your-secret-key
DEBUG=False

# Using python-dotenv
from dotenv import load_dotenv
import os

load_dotenv()
db_url = os.getenv('DATABASE_URL')

# Docker deployment
# Dockerfile
FROM python:3.9
WORKDIR /app
COPY requirements.txt .
RUN pip install -r requirements.txt
COPY . .
EXPOSE 8000
CMD ['gunicorn', '-b', '0.0.0.0:8000', 'app:app']

# docker-compose.yml
version: '3'
services:
  web:
    build: .
    ports:
      - '8000:8000'
    environment:
      - DATABASE_URL=postgresql://...
  db:
    image: postgres
    environment:
      - POSTGRES_PASSWORD=password

# Heroku deployment
# Procfile
web: gunicorn myproject.wsgi:application

# AWS deployment
# Using Elastic Beanstalk
eb init myapp
eb create production
eb deploy

# PythonAnywhere deployment
# Upload files via web interface
# Configure WSGI file
# Set up virtual environment