擅长:python、mysql、java
<p>您可以使用:</p>
<pre><code>from itertools import product
#get unique values only
b = df.b.unique()
#create all combination
df1 = pd.DataFrame(list(product(b, b)), columns=['a', 'b'])
#filtering
df1 = df1[df1.apply(lambda x: x.a in x.b, axis=1) & (df1.a != df1.b)]
print (df1)
a b
1 world helloworld
23 ness greatness
print (df1.a.tolist())
['world', 'ness']
</code></pre>
<p>交叉连接的替代解决方案:</p>
^{pr2}$