def not_empty(s):
  return s and s.strip()
print(list(filter(not_empty, ['A', '', 'B', None,'C', ' '])))

def not_empty(s):
  return s.strip()
print(list(filter(not_empty, ['A', '', 'B', 'C', ' '])))

def str_Nempty(s):
	return list(filter(lambda s: s and s.strip(),s))
print(str_Nempty(['A', '', 'B', 'C', ' ']))