(l)
return " ".join(filter(None, l))
['-a', '', 'abc', ''] -> '-a abc
['-a', '', 'abc', ''] -> '-a abc
[ - a abc ] - > - a abc
def MakeArgs(l):
  """['-a', '', 'abc', ''] -> '-a abc'"""
  return " ".join(filter(None, l))
def MakeArgs ( l ) : return " " . join ( filter ( None , l ) )