复制下面这段代码存为python格式，运行，可自动下载

 

#!/usr/bin/env python"""
Setuptools bootstrapping installer.Maintained at https://github.com/pypa/setuptools/tree/bootstrap.Run this script to install or upgrade setuptools.This method is DEPRECATED. Check https://github.com/pypa/setuptools/issues/581 for more details.
"""import os
import shutil
import sys
import tempfile
import zipfile
import optparse
import subprocess
import platform
import textwrap
import contextlibfrom distutils import logtry:from urllib.request import urlopen
except ImportError:from urllib2 import urlopentry:from site import USER_SITE
except ImportError:USER_SITE = None# 33.1.1 is the last version that supports setuptools self upgrade/installation.
DEFAULT_VERSION = "33.1.1"
DEFAULT_URL = "https://pypi.io/packages/source/s/setuptools/"
DEFAULT_SAVE_DIR = os.curdir
DEFAULT_DEPRECATION_MESSAGE = "ez_setup.py is deprecated and when using it setuptools will be pinned to {0} since it's the last version that supports setuptools self upgrade/installation, check https://github.com/pypa/setuptools/issues/581 for more info; use pip to install setuptools"MEANINGFUL_INVALID_ZIP_ERR_MSG = 'Maybe {0} is corrupted, delete it and try again.'log.warn(DEFAULT_DEPRECATION_MESSAGE.format(DEFAULT_VERSION))def _python_cmd(*args):"""Execute a command.Return True if the command succeeded."""args = (sys.executable,) + argsreturn subprocess.call(args) == 0def _install(archive_filename, install_args=()):"""Install Setuptools."""with archive_context(archive_filename):# installinglog.warn('Installing Setuptools')if not _python_cmd('setup.py', 'install', *install_args):log.warn('Something went wrong during the installation.')log.warn('See the error message above.')# exitcode will be 2return 2def _build_egg(egg, archive_filename, to_dir):"""Build Setuptools egg."""with archive_context(archive_filename):# building an egglog.warn('Building a Setuptools egg in %s', to_dir)_python_cmd('setup.py', '-q', 'bdist_egg', '--dist-dir', to_dir)# returning the resultlog.warn(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 selfdef __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(ContextualZipFile, cls).__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.warn('Extracting in %s', tmpdir)old_wd = os.getcwd()try:os.chdir(tmpdir)try:with ContextualZipFile(filename) as archive:archive.extractall()except zipfile.BadZipfile as err:if not err.args:err.args = ('', )err.args = err.args + (MEANINGFUL_INVALID_ZIP_ERR_MSG.format(filename),)raise# going in the directorysubdir = os.path.join(tmpdir, os.listdir(tmpdir)[0])os.chdir(subdir)log.warn('Now working in %s', subdir)yieldfinally: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 setuptoolssetuptools.bootstrap_install_from = eggdef 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 versionor later cannot be installed."""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_resourcespkg_resources.require("setuptools>=" + version)# a suitable version is already installedreturnexcept ImportError:# pkg_resources not available; setuptools is not installed; downloadpassexcept pkg_resources.DistributionNotFound:# no version of setuptools was found; allow downloadpassexcept 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 isunsafe 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. Pleaseinstall 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 = [importerfor importer in sys.meta_pathif importer.__class__.__module__ != 'pkg_resources.extern']del_modules = [name for name in sys.modulesif 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)raisedef 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 Falsecmd = ['powershell', '-Command', 'echo test']with open(os.path.devnull, 'wb') as devnull:try:subprocess.check_call(cmd, stdout=devnull, stderr=devnull)except Exception:return Falsereturn True
download_file_powershell.viable = has_powershelldef 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 Falsereturn True
download_file_curl.viable = has_curldef 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 Falsereturn True
download_file_wget.viable = has_wgetdef 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: Truedef 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 availableas an sdist for download under the `download_base` URL (which should endwith a '/'). `to_dir` is the directory where the egg will be downloaded.`delay` is the number of seconds to pause before an actual downloadattempt.``downloader_factory`` should be a function taking no arguments andreturning a function for downloading a URL to a target."""# making sure we use the absolute pathto_dir = os.path.abspath(to_dir)zip_name = "setuptools-%s.zip" % versionurl = download_base + zip_namesaveto = os.path.join(to_dir, zip_name)if not os.path.exists(saveto):  # Avoid repeated downloadslog.warn("Downloading %s", url)downloader = downloader_factory()downloader(url, saveto)return os.path.realpath(saveto)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 ignoredreturn optionsdef _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())