擅长:python、mysql、java
<pre><code>import pandas as pd
df = pd.DataFrame(["A", "A", "C", "C", "E", "F", "G"], columns=['letters'])
all_cats = ["A", "B", "C", "D", "E", "F", "G"]
ohe = pd.get_dummies(df['letters'], sparse=True).reindex(all_cats, axis=1, fill_value=0)
>>> ohe
A B C D E F G
0 1 0 0 0 0 0 0
1 1 0 0 0 0 0 0
2 0 0 1 0 0 0 0
3 0 0 1 0 0 0 0
4 0 0 0 0 1 0 0
5 0 0 0 0 0 1 0
6 0 0 0 0 0 0 1
</code></pre>