3pp/pip_bootstrap/pip_bootstrap.py

#!/usr/bin/env python
# Copyright 2018 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
#
# Bootstrap script for installing pip, wheel and setuptools from a folder
# containing those three wheels.
#
# This is inspired by https://bootstrap.pypa.io/get-pip.py, but extremely
# stripped down.

from __future__ import print_function

import os
import sys


def main():
  SCRIPT_DIR = os.path.dirname(__file__)
  PREFIX = sys.argv[1]

  # Find pip wheel in this directory.
  for filename in os.listdir(SCRIPT_DIR):
    if filename.startswith('pip-'):
      sys.path.insert(0, os.path.abspath(os.path.join(SCRIPT_DIR, filename)))
      break
  else:
    assert False, 'pip_bootstrap.py must be run in a directory with a pip wheel'

  # Import pip from wheel we just added to sys.path so we can use it to install
  # pip, setuptools and wheel.
  # pylint: disable=no-name-in-module
  # pylint: disable=no-member
  import pip.__main__

  if sys.platform == 'win32':
    # HACK - We change sys.executable here so that pip generates e.g. pip.exe
    # containing `#!python.exe` instead of `#!C:\abs\path\to\python.exe`. This,
    # in turn, will allow pip and friends to work, as long as `python.exe` is in
    # %PATH%.
    #
    # Additional exe shims will have absolute paths; however we believe that
    # it's acceptable for developers to not relocate their python installations
    # after installing additional pip packages to them, since this is the
    # behavior of stock python. On bots we don't use these exe shims at all, so
    # it's a moot point.
    #
    # Unfortunately, this additionally only works for .exe files, not .bat
    # files, meaning that we'll need to find a way in depot_tools to get the
    # python.exe on %PATH%, instead of python.bat.
    sys.executable = 'python.exe'

  sys.exit(pip.__main__._main([
    # obliterate whatever is there
    'install', '--upgrade', '--force-reinstall', '--ignore-installed',
    # don't talk to the internet
    '--no-index', '--find-links', SCRIPT_DIR,
    # install to this python installation
    '--prefix', PREFIX,
    # log everything we can,
    '-vvv',
    # Which wheels to install
    'pip', 'setuptools', 'wheel'
  ]))


if __name__ == '__main__':
  main()