<p>使用<a href="https://docs.python.org/2/library/itertools.html#itertools.combinations" rel="nofollow noreferrer">^{<cd1>}</a>和<a href="https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.Series.map.html" rel="nofollow noreferrer">^{<cd2>}</a>有一种方法:</p>
<pre><code>from itertools import combinations
# Create mapping Series of questions - answers
q_map = df.drop_duplicates(subset='question').set_index('question')['answer']
# Create DataFrame of all combinations of questions
df2 = pd.DataFrame(combinations(df['question'].unique(), 2), columns=['question1', 'question2'])
# Create duplicate field using the helper mapping Series
df2['duplicate'] = df2['question1'].map(q_map) == df2['question2'].map(q_map)
</code></pre>
<p>[外]</p>
<pre><code> question1 question2 duplicate
0 abc def False
1 abc ghi True
2 abc jkl False
3 abc mno False
4 abc pqr False
5 abc stu False
6 abc vwx True
7 abc yzz False
8 def ghi False
9 def jkl False
10 def mno False
11 def pqr False
12 def stu False
13 def vwx False
14 def yzz False
15 ghi jkl False
16 ghi mno False
17 ghi pqr False
18 ghi stu False
19 ghi vwx True
20 ghi yzz False
21 jkl mno False
22 jkl pqr False
23 jkl stu False
24 jkl vwx False
25 jkl yzz False
26 mno pqr True
27 mno stu False
28 mno vwx False
29 mno yzz False
30 pqr stu False
31 pqr vwx False
32 pqr yzz False
33 stu vwx False
34 stu yzz False
35 vwx yzz False
</code></pre>