擅长:python、mysql、java
<p>这是我的方法</p>
<pre><code>#create mirror values
df['M1'],df['M2'] = df['start'] + df['end'],df['end'] + df['start']
#keep values that exist back and forth
df = df.loc[(df.M1.isin(df.M2))].iloc[:,:6]
#drop where id is less than one
df.drop(df.id.count() <= 1,inplace=True)
#sort output
df.sort_values(by=['id','Time'],ascending=[True,True],inplace=True)
</code></pre>
<p>结果是</p>
<pre><code> id start end count Time Trip
2 2 Prague Vienna 15 5/18/2016 17:55 No
7 2 Vienna Prague 15 5/19/2016 2:45 No
1 15 Paris London 1 5/19/2016 11:50 Yes
4 15 London Paris 8 5/21/2016 13:50 No
</code></pre>