擅长:python、mysql、java
<p>另一种解决方案,使用<a href="https://www.google.ca/search?q=pandas+melt&rlz=1C5CHFA_enGB564GB564&oq=pandas+melt&aqs=chrome..69i57j69i60l2j69i59l2.1287j0j4&sourceid=chrome&ie=UTF-8" rel="nofollow noreferrer">^{<cd1>}</a>:</p>
<pre><code>new_df = (df.melt(['Location','Nominal'],
['Meas1', 'Meas2', 'Meas3'],
value_name = 'Meas')
.drop('variable', axis=1)
.sort_values('Location'))
>>> new_df
Location Nominal Meas
0 A 4.0 3.8
2 A 4.0 4.1
4 A 4.0 4.3
1 B 9.0 8.7
3 B 9.0 8.9
5 B 9.0 9.1
</code></pre>