esp-idf/tools/detect_python.sh

# This file should be sourced, not executed!
#
# This is a helper script for detecting Python executables in the PATH. It is intended to be used for determining
# which Python should be used with idf_tools.py for installing tools and exporting environment variables.
#
# 1. The script is looking for python version same or greater than minimal required version on path
# 2. If required version of python is found it is assigned to environmental variable `ESP_PYTHON`
# 3. If required version of python is not found, script will fail

OLDEST_PYTHON_SUPPORTED_MAJOR=3
OLDEST_PYTHON_SUPPORTED_MINOR=8

ESP_PYTHON=python

for p_cmd in python3 python python3.8 python3.9 python3.10 python3.11 python3.12; do
    $p_cmd --version >/dev/null 2>&1 || continue
    echo "Checking \"$p_cmd\" ..."

    $p_cmd -c "import sys; exit(1) if sys.version_info.major < int(\"$OLDEST_PYTHON_SUPPORTED_MAJOR\") else exit(0);" || continue
    $p_cmd -c "import sys; exit(1) if sys.version_info.minor < int(\"$OLDEST_PYTHON_SUPPORTED_MINOR\") else exit(0);" || continue

    ESP_PYTHON=$p_cmd
    break
done

$ESP_PYTHON --version 2>/dev/null || {
    echo "Python ${OLDEST_PYTHON_SUPPORTED_MAJOR}.${OLDEST_PYTHON_SUPPORTED_MINOR}+ is not installed! Please see the documentation for how to install it."
    exit 1
}
echo "\"$ESP_PYTHON\" has been detected"