请教python怎么把字符串和有权树互换

请问python如何把字符串和有权树互换？
请问我有这样的字符串 [[A:10, B:8, C:7]D:11, E:12, F:13], 我还有个node类， ABCDEF都是node类的对象，我要建立一棵树，R代表根，R有三个子节点DEF， D又有三个子节点ABC， 有没有好的例子可以学习一下阿

如果我建立了这样的一棵树 要如何便利这颗树 也请教有没有这方面的例子 学习一下 谢谢！

[解决办法]

Python code

treestr =  "[[A:10, B:8, C:7]D:11, E:12, F:13]"MyTree = {}def createTree(substring,node):    l = len(substring)    if l == 0:        return    if substring[0] == '[':        c = 1        i = 1        while c != 0 and i < l:            if substring[i] == '[':                c += 1            elif substring[i] == ']':                c -= 1            else :                pass            i += 1        j = i        while  j < l:            if substring[j] == ',':                break            j += 1        if j < l:            #1:i,i:':',':':j            key = substring[i:j].split(':')[0]            value = substring[i:j].split(':')[1]            subtreestring = substring[1:i-1]            #need to treat space........            node[key] = {}            node[key]['value'] = value            node[key]['subkey'] = {}            createTree(subtreestring,node[key]['subkey'])            createTree(substring[j+1:],node)            return    d = substring.split(',')    node[d[0].split(':')[0]] = {}    node[d[0].split(':')[0]]['value']= d[0].split(':')[1]    node[d[0].split(':')[0]]['subtree']= {}    createTree(','.join(d[1:]),node)if __name__ == '__main__':    createTree(treestr[1:-1],MyTree)    print MyTree