what is the fast way to drop columns in pandas dataframe from a list of column names : <p>I'm trying to figure out the fastest way to drop columns in df using a list of column names. this is a fancy feature reduction technique.
This is what I am using now, and it is taking forever. Any suggestions are highly appreciated.</p>

<pre><code>    important2=(important[:-(len(important)-500)]) 
    for i in important:
        if i in important2:
            pass
        else:
            df_reduced.drop(i, axis=1, inplace=True)
    df_reduced.head()
</code></pre>
