擅长:python、mysql、java
<pre><code>d = df.set_index('colour').to_dict()['points']
s = pd.Series(list(itertools.combinations(df.colour, 2)))
s = pd.concat([s, s.transform(lambda k: k[::-1])])
v = s.map(lambda k: d[k[0]] - d[k[1]])
df2= pd.DataFrame({'comb': s.str.get(0)+'_' + s.str.get(1), 'values': v})
comb values
0 red_yellow -9
1 red_black 4
2 yellow_black 13
0 yellow_red 9
1 black_red -4
2 black_yellow -13
</code></pre>