title: Concatenate nested python lists column-wise (similar to numpy.hstack() )
body: <p>I am trying to concatenate two nested lists column-wise in Python. This is similar to numpy.hstack() but is in base Python with Python lists. I am able to do this in the following way. Is there a better, potentially faster way of concatenating nested lists column-wise?</p>
  
  <pre><code>list_a = [[2, 2], [4, 4], [6, 6]]
  list_b = [[1, 1], [3, 3], [5, 5]]
  
  # list_b as array-like
  #[2, 2]
  #[4, 4]
  #[6, 6]
  
  # list_c as array_like
  #[1, 1]
  #[3, 3]
  #[5, 5]
  
  for x,y in zip(list_a,list_b):
      x = x + y
  
  # list_a after concatenation
  #[2, 2, 1, 1]
  #[4, 4, 3, 3]
  #[6, 6, 5, 5]
  </code></pre>