How to fix Error: Can't find Python executable "python", you can set the PYTHON env variable. in Node.js

Python Version Compatibility:
node-gyp v10+ requires Python 3.6 or later. Older versions of node-gyp support Python 2.7, but Python 2 reached end-of-life in 2020 and should be avoided. If you're using an older Node.js version with an old node-gyp, consider upgrading Node.js rather than installing Python 2.

Docker Considerations:
When building Node.js applications in Docker, use base images that include build dependencies:

# Instead of node:alpine
FROM node:18-alpine

# Install Python and build tools
RUN apk add --no-cache python3 make g++

WORKDIR /app
COPY package*.json ./
RUN npm ci --only=production

For Debian-based images:

FROM node:18

RUN apt-get update && apt-get install -y \
    python3 \
    build-essential \
    && rm -rf /var/lib/apt/lists/*

Pre-built Binaries Alternative:
Some packages offer pre-built binaries that don't require compilation. For example, @mapbox/node-pre-gyp downloads pre-compiled binaries when available. Check if your dependency offers this option to avoid the need for Python and build tools entirely.

Windows PATH Configuration:
On Windows, if Python is installed but not found, manually add it to PATH:
1. Search for "Environment Variables" in Windows Settings
2. Edit the "Path" variable under System Variables
3. Add the Python installation directory (e.g., C:\Python39 and C:\Python39\Scripts)
4. Restart your terminal/IDE

Multiple Python Versions:
If you have both Python 2 and Python 3 installed, node-gyp might pick the wrong one. Always explicitly configure which version to use via npm config set python or the --python flag.

CI/CD Configuration:
For GitHub Actions, GitLab CI, or other CI platforms, ensure your pipeline includes Python in the build environment:

# GitHub Actions
- uses: actions/setup-python@v4
  with:
    python-version: '3.10'

# GitLab CI
image: node:18
before_script:
  - apt-get update && apt-get install -y python3 build-essential