title: what does n += 1 in plt.subplot mean
body: <p>I don't understand how the n +=1 variable below made the distplot visualization into 3 columns</p>
  <pre><code>n=0
  for x in ['Age', 'Annual Income (k$)', 'Spending Score (1-100)']:
      n +=1
      plt.subplot(1,3,n)
      plt.subplots_adjust(hspace=0.5,wspace = 0.5)
      sns.distplot(df[x], bins = 20)
      plt.title('Displot of {}'.format(x))
  plt.show()
  </code></pre>
  <p>pls see attached photo of distplot<a href="https://i.stack.imgur.com/KMFZN.png" rel="nofollow noreferrer">enter image description here</a></p>