擅长:python、mysql、java
<p>您可以使用<code>np.where()</code>以向量化的方式轻松解决问题,而不需要<code>apply</code>函数:</p>
<pre><code>df_i2b2['TBI_var'] = np.where(df_i2b2['DIAGNOSIS_CODES'].isna(),np.nan,1)
</code></pre>
<p>这将返回:</p>
<pre><code> id DIAGNOSIS_CODES TBI_var
0 1 338.29; 353.6; 355.9; 722.6; 724.2; E43 1.0
1 2 278.00; 300.00; 305.1; 353.6 1.0
2 3 E66.9; F32.9; F41.9; J96.10; S06 1.0
3 4 NaN NaN
</code></pre>