擅长:python、mysql、java
<p>您可以<code>.reset_index()</code>,熔化并再次设置索引。然后按<code>rating</code>过滤数据帧:</p>
<pre><code>x = (
df.reset_index()
.melt(id_vars="Userid", var_name="movie_id", value_name="rating")
.set_index("Userid")
)
print(x[x["rating"] > 0])
</code></pre>
<p>印刷品:</p>
<pre class="lang-none prettyprint-override"><code> movie_id rating
Userid
u_A 2 1
u_A 4 3
u_A 24 5
u_B 24 1
</code></pre>