擅长:python、mysql、java
<p>尝试,并计算时间,毕竟<code>print(ddf.head(10))</code>以查看输出</p>
<pre><code>from dask import dataframe as dd
ddf = dd.from_pandas(df, npartitions=10)
ddf[(ddf.A == 2) | (ddf.A == 1)]['C'] = ddf['A']
ddf[(ddf.A != 2) & (ddf.A != 1)]['C'] = ddf['B']
print(ddf.head(x))
</code></pre>