title: How to give column names after one-hot encoding with sklearn?
body: <p>Here is my question, I hope someone can help me to figure it out..</p>
  
  <p>To explain, there are more than 10 categorical columns in my data set and each of them has 200-300 categories. I want to convert them into binary values. For that I used first label encoder to convert string categories into numbers. The Label Encoder code and the output is shown below.</p>
  
  <p><img src="https://i.stack.imgur.com/MIVHV.png" alt="https://i.stack.imgur.com/MIVHV.png"></p>
  
  <p>After Label Encoder, I used One Hot Encoder From scikit-learn again and it is worked. BUT THE PROBLEM IS, I need column names after one hot encoder. For example, column A with categorical values before encoding. <code>A = [1,2,3,4,..]</code></p>
  
  <p>It should be like that after encoding,</p>
  
  <blockquote>
    <p>A-1, A-2, A-3</p>
  </blockquote>
  
  <p>Anyone know how to assign column names to (old column names -value name or number) after one hot encoding. Here is my one hot encoding and it's output;</p>
  
  <p><img src="https://i.stack.imgur.com/kgrNa.png" alt="https://i.stack.imgur.com/kgrNa.png"></p>
  
  <p>I need columns with name because I trained an ANN, but every time data comes up I cannot convert all past data again and again. So, I want to add just new ones every time. Thank anyway..</p>