easy_install.py 文件源码

def install_site_py(self):
        """Make sure there's a site.py in the target dir, if needed"""

        if self.sitepy_installed:
            return  # already did it, or don't need to

        sitepy = os.path.join(self.install_dir, "site.py")
        source = resource_string("setuptools", "site-patch.py")
        source = source.decode('utf-8')
        current = ""

        if os.path.exists(sitepy):
            log.debug("Checking existing site.py in %s", self.install_dir)
            with io.open(sitepy) as strm:
                current = strm.read()

            if not current.startswith('def __boot():'):
                raise DistutilsError(
                    "%s is not a setuptools-generated site.py; please"
                    " remove it." % sitepy
                )

        if current != source:
            log.info("Creating %s", sitepy)
            if not self.dry_run:
                ensure_directory(sitepy)
                with io.open(sitepy, 'w', encoding='utf-8') as strm:
                    strm.write(source)
            self.byte_compile([sitepy])

        self.sitepy_installed = True