Dockerfile

# Use Python 3.9 slim image as base, which is a good choice for stability and size.
FROM python:3.9-slim

# Set the working directory inside the container
WORKDIR /app

# Install system dependencies required for RDKit and other graphical libraries.
# This is a crucial step for rdkit-pypi to work correctly in a Linux container.
RUN apt-get update && apt-get install -y \
    gcc \
    g++ \
    libxext6 \
    libxrender1 \
    && rm -rf /var/lib/apt/lists/*

# Copy the requirements file first to leverage Docker's layer caching.
# The Docker build will only re-run the pip install step if this file changes.
COPY requirements.txt .

# Install the Python dependencies specified in requirements.txt
RUN pip install --no-cache-dir -r requirements.txt

# Copy the rest of your application code into the container
COPY . .

# Expose the port that Streamlit will run on. Hugging Face Spaces typically uses 7860.
EXPOSE 7860

# Set environment variables for Streamlit to run in a headless environment.
ENV STREAMLIT_SERVER_ADDRESS=0.0.0.0
ENV STREAMLIT_SERVER_PORT=7860
ENV STREAMLIT_SERVER_HEADLESS=true
ENV STREAMLIT_BROWSER_GATHER_USAGE_STATS=false

# The command to run your Streamlit application when the container starts.
# It points to the app.py file and sets the server address and port.
CMD ["streamlit", "run", "app.py", "--server.port=7860", "--server.address=0.0.0.0"]