import zipfile, os, os.path

class ZipFileExt(zipfile.ZipFile):

    def unzip_into_dir(self, dir):

        if not os.path.exists(dir):

            os.mkdir(dir, 0777)

        for name in self.namelist():

            if name.endswith('/'):

                os.mkdir(os.path.join(dir,name))

            else:

                outfile = open(os.path.join(dir,name), 'wb')

                outfile.write(self.read(name))

                outfile.close()