How to use the setuptools.extern.six function in setuptools

tag, cfglen, bmlen = struct.unpack("

def get_ext_filename(self, fullname):
        filename = _build_ext.get_ext_filename(self, fullname)
        if fullname in self.ext_map:
            ext = self.ext_map[fullname]
            use_abi3 = (
                six.PY3
                and getattr(ext, 'py_limited_api')
                and get_abi3_suffix()
            )
            if use_abi3:
                so_ext = get_config_var('EXT_SUFFIX')
                filename = filename[:-len(so_ext)]
                filename = filename + get_abi3_suffix()
            if isinstance(ext, Library):
                fn, ext = os.path.splitext(filename)
                return self.shlib_compiler.library_filename(fn, libtype)
            elif use_stubs and ext._links_to_dynamic:
                d, fn = os.path.split(filename)
                return os.path.join(d, 'dl-' + fn)
        return filename

for (option, (source, value)) in option_dict.items():
            if DEBUG:
                self.announce("    %s = %s (from %s)" % (option, value,
                                                         source))
            try:
                bool_opts = [translate_longopt(o)
                             for o in command_obj.boolean_options]
            except AttributeError:
                bool_opts = []
            try:
                neg_opt = command_obj.negative_opt
            except AttributeError:
                neg_opt = {}

            try:
                is_string = isinstance(value, six.string_types)
                if option in neg_opt and is_string:
                    setattr(command_obj, neg_opt[option], not strtobool(value))
                elif option in bool_opts and is_string:
                    setattr(command_obj, option, strtobool(value))
                elif hasattr(command_obj, option):
                    setattr(command_obj, option, value)
                else:
                    raise DistutilsOptionError(
                        "error in %s: command '%s' has no such option '%s'"
                        % (source, command_name, option))
            except ValueError as msg:
                raise DistutilsOptionError(msg)

def load_launcher_manifest(name):
    manifest = pkg_resources.resource_string(__name__, 'launcher manifest.xml')
    if six.PY2:
        return manifest % vars()
    else:
        return manifest.decode('utf-8') % vars()

from distutils import log
from distutils.errors import DistutilsOptionError
import os
import socket
import zipfile
import tempfile
import shutil

from setuptools.extern import six
from setuptools.extern.six.moves import http_client, urllib

from pkg_resources import iter_entry_points
from .upload import upload


errors = 'surrogateescape' if six.PY3 else 'strict'


# This is not just a replacement for byte literals
# but works as a general purpose encoder
def b(s, encoding='utf-8'):
    if isinstance(s, six.text_type):
        return s.encode(encoding, errors)
    return s


class upload_docs(upload):
    description = 'Upload documentation to PyPI'

    user_options = [
        ('repository=', 'r',
         "url of repository [default: %s]" % upload.DEFAULT_REPOSITORY),

def load_launcher_manifest(name):
    manifest = pkg_resources.resource_string(__name__, 'launcher manifest.xml')
    if six.PY2:
        return manifest % vars()
    else:
        return manifest.decode('utf-8') % vars()

def load_launcher_manifest(name):
    manifest = pkg_resources.resource_string(__name__, 'launcher manifest.xml')
    if six.PY2:
        return manifest % vars()
    else:
        return manifest.decode('utf-8') % vars()

def create_home_path(self):
        """Create directories under ~."""
        if not self.user:
            return
        home = convert_path(os.path.expanduser("~"))
        for name, path in six.iteritems(self.config_vars):
            if path.startswith(home) and not os.path.isdir(path):
                self.debug_print("os.makedirs('%s', 0o700)" % path)
                os.makedirs(path, 0o700)

def create_home_path(self):
        """Create directories under ~."""
        if not self.user:
            return
        home = convert_path(os.path.expanduser("~"))
        for name, path in six.iteritems(self.config_vars):
            if path.startswith(home) and not os.path.isdir(path):
                self.debug_print("os.makedirs('%s', 0o700)" % path)
                os.makedirs(path, 0o700)

def write_file(self, what, filename, data):
        """Write `data` to `filename` (if not a dry run) after announcing it

        `what` is used in a log message to identify what is being written
        to the file.
        """
        log.info("writing %s to %s", what, filename)
        if six.PY3:
            data = data.encode("utf-8")
        if not self.dry_run:
            f = open(filename, 'wb')
            f.write(data)
            f.close()