python非递归全排列实现方法

def getArrayInsertCharToStr(STR,CHAR):  arr =[]  s_len = len(STR)  index =0  while index <= s_len:    #分割字符串    arr.append(STR[:index]+CHAR+STR[index:s_len])    index = index + 1  return arr  def getArrayInsertCharToArray(array,CHAR):  index = 0  re_array = []  while index < len(array):    re_array = re_array + getArrayInsertCharToStr(array[index],CHAR)    index = index + 1  return re_array       def getPermutation(STR):    resultArr = [STR[0]]    for item in STR[1:]:      resultArr = getArrayInsertCharToArray(resultArr,item)    return   resultArrprint(getPermutation('abc'))