擅长:python、mysql、java
<p>很明显,您也在添加字符串,因为<code>total += months[r][c]</code>可以是<code>total += months[0][0]</code>,也就是一个字符串</p>
<p>相反,您可以这样做:</p>
<pre><code>def total_Rainfall(months):
total = 0
for row in months:
total += row[1] # always use the second column
print('The total rainfall for the year is ', total, ' inches.')
</code></pre>
<p>因此,如果我们用以下数据来尝试:</p>
<pre><code>months = [
['Jan', 2.3],
['Feb', 3.3],
['Mar', 3.2]
]
total_Rainfall(months)
</code></pre>
<p>我们得到:</p>
<pre><code>The total rainfall for the year is 8.8 inches.
</code></pre>