"""
完成一个句子的倒叙,单词中的字母顺序不变
输入:      输出:
1          1
’  1‘      ’1  ‘
...
"""
def revers_str(str_old):
    l_s = list(str_old) #string 转list
    a = len(l_s)
    newStr = ''
    newTab = ''
    newList = []
    str_new = ''
    for i in range(a):
        if l_s[i] != ' ': #空格串不为空则添加到数组,重置空格串为空,判断元素为字母并且拼接
            if newTab != '':
                newList.append(newTab)
            newTab = ''
            newStr += l_s[i]
        else:#单词串不为空则添加到数组,重置单词串为空,判断元素为空格并且拼接
            if newStr != '':
                newList.append(newStr)
            newStr = ''
            newTab += l_s[i]
        if i == a-1:
            if newTab != '':
                newList.append(newTab)
            else:
                newList.append(newStr)

    newList.reverse()
    for str in newList:
        str_new += str
    print(str_new)

revers_str("    13E 2RRRV    3RRR   ")