擅长:python、mysql、java
<p>您可以用<code>NaN</code>替换<code>0</code>,然后使用<a href="https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.stack.html" rel="nofollow noreferrer">^{<cd3>}</a></p>
<pre><code>df.rename_axis("movie_id", axis=1).replace(0, np.nan).stack().reset_index(
name="rating"
)
Userid movie_id rating
0 u_A 2 1.0
1 u_A 4 3.0
2 u_A 24 5.0
3 u_B 24 1.0
</code></pre>