<p>您可以使用<a href="http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.loc.html" rel="nofollow noreferrer">^{<cd1>}</a>+<a href="http://pandas.pydata.org/pandas-docs/stable/generated/pandas.Series.values.html" rel="nofollow noreferrer">^{<cd2>}</a>将<code>Serie</code>转换为<code>numpy array</code>,然后通过<code>[0]</code>选择第一个值:</p>
<pre><code>print (df.loc[df.name == 'george', 'age'].values)
[23]
print (df.loc[df.name == 'george', 'age'].values[0])
23
</code></pre>
<p>或者只需使用<a href="http://pandas.pydata.org/pandas-docs/stable/generated/pandas.Series.iloc.html" rel="nofollow noreferrer">^{<cd7>}</a>选择<code>Series</code>的第一个值:</p>
<pre><code>print (df.loc[df.name == 'george', 'age'].iloc[0])
23
</code></pre>
<p>或按<a href="http://pandas.pydata.org/pandas-docs/stable/generated/pandas.Series.iat.html" rel="nofollow noreferrer">^{<cd8>}</a>选择第一项:</p>
<pre><code>print (df.loc[df.name == 'george', 'age'].iat[0])
23
</code></pre>
<p>或者使用<a href="http://pandas.pydata.org/pandas-docs/stable/generated/pandas.Series.item.html" rel="nofollow noreferrer">^{<cd9>}</a>:</p>
<pre><code>print (df.loc[df.name == 'george', 'age'].item())
23
</code></pre>
<hr/>
<p>如果可能没有匹配值,则上述解决方案失败。</p>
<p>然后可以使用<code>next</code>和<code>iter</code>技巧:</p>
<pre><code>print (next(iter(df.loc[df.name == 'george', 'age']),'no match value'))
23
print (next(iter(df.loc[df.name == 'jano z hornej dolnej', 'age']),'no match value'))
no match value
</code></pre>