擅长:python、mysql、java
<pre><code>difference = lambda x: ['x['Allotment'][0], x.ix[1]['NDII_Mean'] - x.ix[0]['NDII_Mean']]
df_diffs = DataFrame([difference(x[1].reset_index(drop = True)) for x in df.groupby(['Allotment'])])
df_diffs.columns = ['Allotment', 'NDII_Mean']
print df_diffs
Allotment NDII_Mean
0 A_Annex 0.55756
1 Arnstson -0.02747
</code></pre>