python 爬取网页上的网址 为什么只爬到一个字符串

<h1>2018-09-17 京豆链接数据</h1>
<p>京豆【1】东卷【满10-5】积分【30】<a href='https://mall.jd.com/index-99005.html' target='_blank'>https://mall.jd.com/index-99005.html</a></p><p>京豆【2】<a href='https://mall.jd.com/index-99017.html' target='_blank'>https://mall.jd.com/index-99017.html</a></p><p>京豆【1】<a href='https://mall.jd.com/index-82441.html' target='_blank'>https://mall.jd.com/index-82441.html</a></p><p>东卷【满10-5】京豆【1】积分【100】<a href='https://mall.jd.com/index-658698.html' target='_blank'>https://mall.jd.com/index-658698.html</a></p><p>京豆【1】东卷【满10-5】积分【88】<a href='https://mall.jd.com/index-655045.html' target='_blank'>https://mall.jd.com/index-655045.html</a></p><p>东卷【满199-40】京豆【1】<a href='https://mall.jd.com/index-661887.html' target='_blank'>https://mall.jd.com/index-661887.html</a></p><p>京豆【10】<a href='https://mall.jd.com/index-1000005719.html' target='_blank'>https://mall.jd.com/index-1000005719.html</a></p><p>京豆【10】<a href='https://mall.jd.com/index-1000000263.html' target='_blank'>https://mall.jd.com/index-1000000263.html</a></p><p>京豆【10】<a href='https://mall.jd.com/index-600733.html' target='_blank'>https://mall.jd.com/index-600733.html</a></p><p>京豆【10】<a href='https://mall.jd.com/index-1000102770.html' target='_blank'>https://mall.jd.com/index-1000102770.html</a></p><p>京豆【1】东卷【满59-10】<a href='https://mall.jd.com/index-773233.html' target='_blank'>https://mall.jd.com/index-773233.html</a></p><p>京豆【5】<a href='https://mall.jd.com/index-190936.html' target='_blank'>https://mall.jd.com/index-190936.html</a></p><p>京豆【5】东卷【满500-30】<a href='https://mall.jd.com/index-750258.html' target='_blank'>https://mall.jd.com/index-750258.html</a></p><p>京豆【5】东卷【满100-5】<a href='https://mall.jd.com/index-706169.html'