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<p>我需要基于<code>frame</code>列透视或重塑这个数据帧</p>
<p><code>df = {'frame': {0: 0, 1: 1, 2: 2, 3: 0, 4: 1, 5: 2}, 'pvol': {0: nan, 1: nan, 2: nan, 3: 23.1, 4: 24.3, 5: 25.6}, 'vvol': {0: 109.8, 1: 140.5, 2: 160.4, 3: nan, 4: nan, 5: nan}, 'area': {0: 120, 1: 130, 2: 140, 3: 110, 4: 110, 5: 112}, 'label': {0: 'v', 1: 'v', 2: 'v', 3: 'p', 4: 'p', 5: 'p'}}</code></p>
<p>当前数据帧</p>
<pre><code>frame pvol vvol area label
0 NaN 109.8 120 v
1 NaN 140.5 130 v
2 NaN 160.4 140 v
0 23.1 NaN 110 p
1 24.3 NaN 110 p
2 25.6 NaN 112 p
</code></pre>
<p>预期产量</p>
<pre><code>frame pvol vvol v_area p_area
0 23.1 109.8 110 110
1 24.3 140.5 110 110
2 25.6 160.4 112 112
</code></pre>
<p>前缀<code>v</code>和<code>p</code>不是必需的,我只是需要一种区分列的方法</p>
<p>这就是我如何让它工作的,但它似乎很长。我相信有更好的办法</p>
<pre><code>for name, tdf in df.groupby('label'):
df.loc[tdf.index, '{}_area'.format(name)] = tdf['area']
pdf = df[df['label'].eq('p')][['frame', 'label', 'pvol', 'p_area']]
vdf = df[df['label'].eq('v')][['frame', 'vvol', 'v_area']]
df = pdf.merge(vdf, on='frame', how='outer')
</code></pre>