Docker for Python Developers: From Zero to Containerized App

Docker changed how we deploy applications. No more "it works on my machine" problems. Here's everything a Python developer needs to know to get started with Docker. Why Docker? Before Docker: "Works on my machine" Complex environment setup Dependency conflicts Hard to scale With Docker: Consistent environments everywhere One command setup Isolated dependencies Easy horizontal scaling Your First Dockerfile # Dockerfile FROM python:3.11-slim # Set working directory WORKDIR /app # Copy requirements first (for layer caching) COPY requirements.txt . # Install dependencies RUN pip install --no-cache-dir -r requirements.txt # Copy application code COPY . . # Expose port EXPOSE 8000 # Run the application CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"] Sample FastAPI App # main.py from fastapi import FastAPI app = FastAPI () @app.get ( " / " ) def read_root (): return { " message " : " Hello from Docker! " } @app.get ( " /health " ) def health_check (): return { " status " :