title: is Pandas concat an in-place function?
body: <p>I guess this question needs some insight into the implementation of concat.</p>
  
  <p>Say, I have 30 files, 1G each, and I can only use up to 32 G memory. I loaded the files into a list of DataFrames, called 'list_of_pieces'. This list_of_pieces should be ~ 30G in size, right?</p>
  
  <p>if I do 'pd.concat(list_of_pieces)', does concat allocate another 30G (or maybe 10G 15G) in the heap and do some operations, or it run the concatation 'in-place' without allocating new memory?</p>
  
  <p>anyone knows this?</p>
  
  <p>Thanks!</p>