擅长:python、mysql、java
<p><code>cursor.fetchall()</code><a href="https://dev.mysql.com/doc/connector-python/en/connector-python-api-mysqlcursor-fetchall.html" rel="nofollow noreferrer">returns a list of tuples</a>。你知道吗</p>
<p>这意味着<code>data[i]</code>将是<code>tuple</code>,根据定义,它是不可变的。如果您想修改<code>data[i]</code>,您需要将元组转换成列表</p>
<pre><code>data = [list(row) for row in Tdata]
</code></pre>
<p>或者通过元组连接替换整行</p>
<pre><code>data[i] = data[i][:4] + (MPLCount,) + data[i][5:]
</code></pre>