title: Using sklearn ColumnTransformer function. What do the paremeters do?
body: <p>can anyone please explain the parameters passed into ColumnTransformer</p>
  
  <pre><code>Column_Trans=ColumnTransformer([('encoder',OneHotEncoder(),[0])],remainder='passthrough')
  </code></pre>
  
  <p>I specifically have no intuituve idea of what [0] is doing as when I change the value I get errors that dont make sense. I also think that 'passthrough' grabs the columns we didnt specify and encodes then but i dont understand how it doesn't grab columns that aren't categorical values. </p>