Join a list of lists together into one list in Python [duplicate]

Answer 1

Yes, here's one way to do it:

def flatten(lst):
    for elem in lst:
        if type(elem) in (tuple, list):
            for i in flatten(elem):
                yield i
        else:
            yield elem

Please note, this creates a generator, so if you need a list, wrap it in list():

flattenedList = list(flatten(nestedList))

Answer 2

Stolen from MonkeySage, here:

def iter_flatten(iterable):
  it = iter(iterable)
  for e in it:
    if isinstance(e, (list, tuple)):
      for f in iter_flatten(e):
        yield f
    else:
      yield e