擅长:python、mysql、java
<p>您需要的是<a href="https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.combine_first.html" rel="nofollow noreferrer">^{<cd1>}</a>:</p>
<pre><code>data4 = {'col1': [1, 2], 'col2': [3, 4]}
df4 = pd.DataFrame(data=data4)
data5 = {'col1': [1, 2], 'col2': [3, 4], 'col3': [9, 2]}
df5 = pd.DataFrame(data=data5)
data6 = {'col1': [1, 2], 'col2': [3, 4], 'col3': [9, 2]}
df6 = pd.DataFrame(data=data6)
print (df4.combine_first(df5).combine_first(df6))
col1 col2 col3
0 1 3 9.0
1 2 4 2.0
</code></pre>