擅长:python、mysql、java
<p>使用<code>merge</code>:</p>
<pre><code>df = pd.DataFrame({'Letters':['A','B', 'D', 'Z']})
all_letters = ['A','B', 'C', 'D','E','K', 'Z']
s = pd.get_dummies(all_letters)
s['Letters'] = all_letters
df2 = df.merge(s, on='Letters')
df2
</code></pre>
<p>给予</p>
<pre><code>| | Letters | A | B | C | D | E | K | Z |
| -:|: | :| :| :| :| :| :| :|
| 0 | A | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
| 1 | B | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
| 2 | D | 0 | 0 | 0 | 1 | 0 | 0 | 0 |
| 3 | Z | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
</code></pre>