分析3.6.1实例，下列（）代码存在错误。<br>（1）def page_request(url, ua):<br>response = requests.get(url, headers=ua)<br>html = response.content.decode('utf-8')<br>return html<br>（2）def save_txt(info_list):<br>import json<br>with open(r'D:\\sentence.txt', 'a', encoding='utf-8') as txt_file:<br>for element in info_list1]:<br>txt_file.write(json.dumps(element,ensure_ascii=False)+'\n\n')<br>（3）def sub_page_parse(sub_html):<br>poem_list = ]<br>for html in sub_html:<br>soup = BeautifulSoup(html, 'lxml')<br>poem = soup.select('div.left &gt; div.sons &gt; div.cont &gt; div.contson')<br>poem = poem0]<br>poem_list.append(poem.strip())<br>return poem_list<br>（4）def sub_page_save(poem_list):<br>import json<br>with open(r'D:\\poems.txt', 'a', encoding='utf-8') as txt_file:<br>for element in poem_list:<br> txt_file.write(json.dumps(element, ensure_ascii=False)+'\n\n')