pythoninstall.py

import sys
import os
import platform
import subprocess
import urllib.request
from urllib.error import URLError, HTTPError
import re

# Base HTTP URL for downloads and version listing
BASE_HTTP = 'https://www.python.org/ftp/python'
LISTING_URL = BASE_HTTP + '/'


def fetch_all_versions():
    """Fetch all available Python versions by scraping the FTP directory listing."""
    try:
        with urllib.request.urlopen(LISTING_URL) as resp:
            html = resp.read().decode('utf-8', errors='ignore')
    except (URLError, HTTPError) as e:
        print(f"Error fetching version listing: {e}")
        sys.exit(1)

    # Find entries like '3.9.18/'
    found = re.findall(r'href=["\'](\d+\.\d+\.\d+)/["\']', html)
    versions = sorted(set(found), key=lambda v: list(map(int, v.split('.'))))
    return versions


def filter_patches(versions, major):
    """Return all patch versions matching the given major (e.g. '3.9')."""
    prefix = major + '.'
    return [v for v in versions if v.startswith(prefix)]


def download_file(url, dest):
    print(f"Downloading {url}...")
    try:
        urllib.request.urlretrieve(url, dest)
    except Exception as e:
        print(f"Download failed: {e}")
        sys.exit(1)
    print(f"Saved to {dest}")
    return dest


def install_on_windows(installer_path):
    print("Running Windows installer (quiet, all users)...")
    try:
        subprocess.run([installer_path, '/quiet', 'InstallAllUsers=1', 'PrependPath=1'], check=True)
        print("Installation complete.")
    except subprocess.CalledProcessError as e:
        print(f"Windows installation failed: {e}")
        sys.exit(1)


def install_on_linux(source_tar):
    print("Installing from source (Linux)...")
    work_dir = "/tmp/python_install"
    os.makedirs(work_dir, exist_ok=True)
    try:
        subprocess.run(["tar", "-xf", source_tar, "-C", work_dir], check=True)
        src_dir = os.path.join(work_dir, os.listdir(work_dir)[0])
        os.chdir(src_dir)
        subprocess.run(["./configure", "--enable-optimizations"], check=True)
        subprocess.run(["make", "-j$(nproc)"], shell=True, check=True)
        subprocess.run(["sudo", "make", "altinstall"], check=True)
        print("Linux installation complete.")
    except subprocess.CalledProcessError as e:
        print(f"Linux installation failed: {e}")
        sys.exit(1)


def main():
    majors = ['3.13', '3.12', '3.11', '3.10', '3.9', '3.8', '3.7', '3.6', '3.5']
    print("Fetching available versions, please wait...")
    all_versions = fetch_all_versions()

    print("Choose a Python major version to install:")
    for idx, ver in enumerate(majors, start=1):
        print(f"{idx}. Python {ver}")
    choice = input('Enter number: ').strip()
    if not choice.isdigit() or not (1 <= int(choice) <= len(majors)):
        print("Invalid selection.")
        sys.exit(1)
    major = majors[int(choice) - 1]
    print(f"You chose Python {major}.")

    patches = filter_patches(all_versions, major)
    if not patches:
        print(f"No patch versions found for Python {major}.")
        sys.exit(1)

    print("1. Install latest patch for this major")
    print("2. Choose a specific patch version")
    sub = input('Enter option [1-2]: ').strip()
    if sub not in ('1', '2'):
        print("Invalid option.")
        sys.exit(1)

    if sub == '1':
        target_version = patches[-1]
    else:
        print("Available patches:")
        for idx, p in enumerate(patches, start=1):
            print(f"{idx}. {p}")
        p_choice = input('Select patch #: ').strip()
        if not p_choice.isdigit() or not (1 <= int(p_choice) <= len(patches)):
            print("Invalid patch selection.")
            sys.exit(1)
        target_version = patches[int(p_choice) - 1]

    print(f"Preparing to install Python {target_version}...")
    system = platform.system()
    if system == 'Windows':
        filename = f"python-{target_version}-amd64.exe"
        url = f"{BASE_HTTP}/{target_version}/{filename}"
        dest = os.path.join(os.getcwd(), filename)
        download_file(url, dest)
        install_on_windows(dest)
    elif system == 'Linux':
        filename = f"Python-{target_version}.tgz"
        url = f"{BASE_HTTP}/{target_version}/{filename}"
        dest = os.path.join('/tmp', filename)
        download_file(url, dest)
        install_on_linux(dest)
    else:
        print(f"Unsupported OS: {system}")
        sys.exit(1)

if __name__ == '__main__':
    main()