30-seconds-of-code/snippets/spread.md

title, tags

title	tags
spread	list,utility,intermediate

Flattens a list, by spreading its elements into a new list.

Loop over elements, use list.extend() if the element is a list, list.append() otherwise.

def spread(arg):
  ret = []
  for i in arg:
    if isinstance(i, list):
      ret.extend(i)
    else:
      ret.append(i)
  return ret

spread([1,2,3,[4,5,6],[7],8,9]) # [1,2,3,4,5,6,7,8,9]