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")
        current = ""

        if os.path.exists(sitepy):
            log.debug("Checking existing site.py in %s", self.install_dir)
            f = open(sitepy, 'rb')
            current = f.read()
            # we want str, not bytes
            if PY3:
                current = current.decode()

            f.close()
            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)
                f = open(sitepy, 'wb')
                f.write(source)
                f.close()
            self.byte_compile([sitepy])

        self.sitepy_installed = True