擅长:python、mysql、java
<p>如果您对转换为分类代码并能够通过字典访问映射感兴趣,<a href="https://pandas.pydata.org/pandas-docs/stable/generated/pandas.factorize.html" rel="nofollow noreferrer">^{<cd1>}</a>可能更方便。在</p>
<p>跨列<a href="https://stackoverflow.com/a/26977495/9209546">via @AlexRiley</a>获取唯一值的算法。在</p>
<pre><code>a = pd.DataFrame({'A':list('bbaba'), 'B':list('cccaa')})
fact = dict(zip(*pd.factorize(pd.unique(a[['A', 'B']].values.ravel('K')))[::-1]))
b = a.applymap(fact.get)
</code></pre>
<p>结果:</p>
^{pr2}$