text: #!/usr/bin/env python
  
  """
  Setuptools bootstrapping installer.
  
  Maintained at https://github.com/pypa/setuptools/tree/bootstrap.
  
  Run this script to install or upgrade setuptools.
  """
  
  import codecs
  import contextlib
  import json
  import optparse
  import os
  import platform
  import shutil
  import subprocess
  import sys
  import tempfile
  import textwrap
  import zipfile
  from distutils import log
  
  try:
      from urllib.parse import urljoin
      from urllib.request import urlopen
  except ImportError:
      from urllib2 import urlopen
      from urlparse import urljoin
  
  try:
      from site import USER_SITE
  except ImportError:
      USER_SITE = None
  
  LATEST = object()
  DEFAULT_VERSION = LATEST
  DEFAULT_URL = "https://pypi.io/packages/source/s/setuptools/"
  DEFAULT_SAVE_DIR = os.curdir
  
  
  def _python_cmd(*args):
      """
      Execute a command.
  
      Return True if the command succeeded.
      """
      args = (sys.executable,) + args
      return subprocess.call(args) == 0
  
  
  def _install(archive_filename, install_args=()):
      """Install Setuptools."""
      with archive_context(archive_filename):
          # installing
          log.warning("Installing Setuptools")
          if not _python_cmd("setup.py", "install", *install_args):
              log.warning("Something went wrong during the installation.")
              log.warning("See the error message above.")
              # exitcode will be 2
              return 2
  
  
  def _build_egg(egg, archive_filename, to_dir):
      """Build Setuptools egg."""
      with archive_context(archive_filename):
          # building an egg
          log.warning("Building a Setuptools egg in %s", to_dir)
          _python_cmd("setup.py", "-q", "bdist_egg", "--dist-dir", to_dir)
      # returning the result
      log.warning(egg)
      if not os.path.exists(egg):
          raise IOError("Could not build the egg.")
  
  
  class ContextualZipFile(zipfile.ZipFile):
  
      """Supplement ZipFile class to support context manager for Python 2.6."""
  
      def __enter__(self):
          return self
  
      def __exit__(self, type, value, traceback):
          self.close()
  
      def __new__(cls, *args, **kwargs):
          """Construct a ZipFile or ContextualZipFile as appropriate."""
          if hasattr(zipfile.ZipFile, "__exit__"):
              return zipfile.ZipFile(*args, **kwargs)
          return super().__new__(cls)
  
  
  @contextlib.contextmanager
  def archive_context(filename):
      """
      Unzip filename to a temporary directory, set to the cwd.
  
      The unzipped target is cleaned up after.
      """
      tmpdir = tempfile.mkdtemp()
      log.warning("Extracting in %s", tmpdir)
      old_wd = os.getcwd()
      try:
          os.chdir(tmpdir)
          with ContextualZipFile(filename) as archive:
              archive.extractall()
  
          # going in the directory
          subdir = os.path.join(tmpdir, os.listdir(tmpdir)[0])
          os.chdir(subdir)
          log.warning("Now working in %s", subdir)
          yield
  
      finally:
          os.chdir(old_wd)
          shutil.rmtree(tmpdir)
  
  
  def _do_download(version, download_base, to_dir, download_delay):
      """Download Setuptools."""
      py_desig = "py{sys.version_info[0]}.{sys.version_info[1]}".format(sys=sys)
      tp = "setuptools-{version}-{py_desig}.egg"
      egg = os.path.join(to_dir, tp.format(**locals()))
      if not os.path.exists(egg):
          archive = download_setuptools(version, download_base, to_dir, download_delay)
          _build_egg(egg, archive, to_dir)
      sys.path.insert(0, egg)
  
      # Remove previously-imported pkg_resources if present (see
      # https://bitbucket.org/pypa/setuptools/pull-request/7/ for details).
      if "pkg_resources" in sys.modules:
          _unload_pkg_resources()
  
      import setuptools
  
      setuptools.bootstrap_install_from = egg
  
  
  def use_setuptools(
      version=DEFAULT_VERSION, download_base=DEFAULT_URL, to_dir=DEFAULT_SAVE_DIR, download_delay=15
  ):
      """
      Ensure that a setuptools version is installed.
  
      Return None. Raise SystemExit if the requested version
      or later cannot be installed.
      """
      version = _resolve_version(version)
      to_dir = os.path.abspath(to_dir)
  
      # prior to importing, capture the module state for
      # representative modules.
      rep_modules = "pkg_resources", "setuptools"
      imported = set(sys.modules).intersection(rep_modules)
  
      try:
          import pkg_resources
  
          pkg_resources.require("setuptools>=" + version)
          # a suitable version is already installed
          return
      except ImportError:
          # pkg_resources not available; setuptools is not installed; download
          pass
      except pkg_resources.DistributionNotFound:
          # no version of setuptools was found; allow download
          pass
      except pkg_resources.VersionConflict as VC_err:
          if imported:
              _conflict_bail(VC_err, version)
  
          # otherwise, unload pkg_resources to allow the downloaded version to
          #  take precedence.
          del pkg_resources
          _unload_pkg_resources()
  
      return _do_download(version, download_base, to_dir, download_delay)
  
  
  def _conflict_bail(VC_err, version):
      """
      Setuptools was imported prior to invocation, so it is
      unsafe to unload it. Bail out.
      """
      conflict_tmpl = textwrap.dedent(
          """
          The required version of setuptools (>={version}) is not available,
          and can't be installed while this script is running. Please
          install a more recent version first, using
          'easy_install -U setuptools'.
  
          (Currently using {VC_err.args[0]!r})
          """
      )
      msg = conflict_tmpl.format(**locals())
      sys.stderr.write(msg)
      sys.exit(2)
  
  
  def _unload_pkg_resources():
      sys.meta_path = [
          importer
          for importer in sys.meta_path
          if importer.__class__.__module__ != "pkg_resources.extern"
      ]
      del_modules = [name for name in sys.modules if name.startswith("pkg_resources")]
      for mod_name in del_modules:
          del sys.modules[mod_name]
  
  
  def _clean_check(cmd, target):
      """
      Run the command to download target.
  
      If the command fails, clean up before re-raising the error.
      """
      try:
          subprocess.check_call(cmd)
      except subprocess.CalledProcessError:
          if os.access(target, os.F_OK):
              os.unlink(target)
          raise
  
  
  def download_file_powershell(url, target):
      """
      Download the file at url to target using Powershell.
  
      Powershell will validate trust.
      Raise an exception if the command cannot complete.
      """
      target = os.path.abspath(target)
      ps_cmd = (
          "[System.Net.WebRequest]::DefaultWebProxy.Credentials = "
          "[System.Net.CredentialCache]::DefaultCredentials; "
          '(new-object System.Net.WebClient).DownloadFile("%(url)s", "%(target)s")' % locals()
      )
      cmd = [
          "powershell",
          "-Command",
          ps_cmd,
      ]
      _clean_check(cmd, target)
  
  
  def has_powershell():
      """Determine if Powershell is available."""
      if platform.system() != "Windows":
          return False
      cmd = ["powershell", "-Command", "echo test"]
      with open(os.path.devnull, "wb") as devnull:
          try:
              subprocess.check_call(cmd, stdout=devnull, stderr=devnull)
          except Exception:
              return False
      return True
  
  
  download_file_powershell.viable = has_powershell
  
  
  def download_file_curl(url, target):
      cmd = ["curl", url, "--location", "--silent", "--output", target]
      _clean_check(cmd, target)
  
  
  def has_curl():
      cmd = ["curl", "--version"]
      with open(os.path.devnull, "wb") as devnull:
          try:
              subprocess.check_call(cmd, stdout=devnull, stderr=devnull)
          except Exception:
              return False
      return True
  
  
  download_file_curl.viable = has_curl
  
  
  def download_file_wget(url, target):
      cmd = ["wget", url, "--quiet", "--output-document", target]
      _clean_check(cmd, target)
  
  
  def has_wget():
      cmd = ["wget", "--version"]
      with open(os.path.devnull, "wb") as devnull:
          try:
              subprocess.check_call(cmd, stdout=devnull, stderr=devnull)
          except Exception:
              return False
      return True
  
  
  download_file_wget.viable = has_wget
  
  
  def download_file_insecure(url, target):
      """Use Python to download the file, without connection authentication."""
      src = urlopen(url)
      try:
          # Read all the data in one block.
          data = src.read()
      finally:
          src.close()
  
      # Write all the data in one block to avoid creating a partial file.
      with open(target, "wb") as dst:
          dst.write(data)
  
  
  download_file_insecure.viable = lambda: True
  
  
  def get_best_downloader():
      downloaders = (
          download_file_powershell,
          download_file_curl,
          download_file_wget,
          download_file_insecure,
      )
      viable_downloaders = (dl for dl in downloaders if dl.viable())
      return next(viable_downloaders, None)
  
  
  def download_setuptools(
      version=DEFAULT_VERSION,
      download_base=DEFAULT_URL,
      to_dir=DEFAULT_SAVE_DIR,
      delay=15,
      downloader_factory=get_best_downloader,
  ):
      """
      Download setuptools from a specified location and return its filename.
  
      `version` should be a valid setuptools version number that is available
      as an sdist for download under the `download_base` URL (which should end
      with a '/'). `to_dir` is the directory where the egg will be downloaded.
      `delay` is the number of seconds to pause before an actual download
      attempt.
  
      ``downloader_factory`` should be a function taking no arguments and
      returning a function for downloading a URL to a target.
      """
      version = _resolve_version(version)
      # making sure we use the absolute path
      to_dir = os.path.abspath(to_dir)
      zip_name = "setuptools-%s.zip" % version
      url = download_base + zip_name
      saveto = os.path.join(to_dir, zip_name)
      if not os.path.exists(saveto):  # Avoid repeated downloads
          log.warning("Downloading %s", url)
          downloader = downloader_factory()
          downloader(url, saveto)
      return os.path.realpath(saveto)
  
  
  def _resolve_version(version):
      """
      Resolve LATEST version
      """
      if version is not LATEST:
          return version
  
      meta_url = urljoin(DEFAULT_URL, "/pypi/setuptools/json")
      resp = urlopen(meta_url)
      with contextlib.closing(resp):
          try:
              charset = resp.info().get_content_charset()
          except Exception:
              # Python 2 compat; assume UTF-8
              charset = "UTF-8"
          reader = codecs.getreader(charset)
          doc = json.load(reader(resp))
  
      return str(doc["info"]["version"])
  
  
  def _build_install_args(options):
      """
      Build the arguments to 'python setup.py install' on the setuptools package.
  
      Returns list of command line arguments.
      """
      return ["--user"] if options.user_install else []
  
  
  def _parse_args():
      """Parse the command line for options."""
      parser = optparse.OptionParser()
      parser.add_option(
          "--user",
          dest="user_install",
          action="store_true",
          default=False,
          help="install in user site package",
      )
      parser.add_option(
          "--download-base",
          dest="download_base",
          metavar="URL",
          default=DEFAULT_URL,
          help="alternative URL from where to download the setuptools package",
      )
      parser.add_option(
          "--insecure",
          dest="downloader_factory",
          action="store_const",
          const=lambda: download_file_insecure,
          default=get_best_downloader,
          help="Use internal, non-validating downloader",
      )
      parser.add_option(
          "--version",
          help="Specify which version to download",
          default=DEFAULT_VERSION,
      )
      parser.add_option(
          "--to-dir",
          help="Directory to save (and re-use) package",
          default=DEFAULT_SAVE_DIR,
      )
      options, args = parser.parse_args()
      # positional arguments are ignored
      return options
  
  
  def _download_args(options):
      """Return args for download_setuptools function from cmdline args."""
      return dict(
          version=options.version,
          download_base=options.download_base,
          downloader_factory=options.downloader_factory,
          to_dir=options.to_dir,
      )
  
  
  def main():
      """Install or upgrade setuptools and EasyInstall."""
      options = _parse_args()
      archive = download_setuptools(**_download_args(options))
      return _install(archive, _build_install_args(options))
  
  
  if __name__ == "__main__":
      sys.exit(main())
  