r xml合并列出函数中的元素，在函数内部时返回错误

我是

R

新手。在

R

中，我试图从

XML节点的各个级别提取一些数据，并将其放入一个数据帧中

我想出的代码是这样的：

src <- sapply(node[[1]][1:5], function(x)  # extract data from first 5 sub-sub-nodes of 1st sub-node (example)
 {

      names <- xpathSApply(x, "choice", xmlGetAttr, "name") # return list of vectors
      ids <- xpathSApply(x, "choice", xmlGetAttr, "id") # return list of vectors
      names2 <- xpathSApply(x, ".", xmlGetAttr, "name") # return list of vectors

      # merge lists together
      final_list <- mapply(rbind, names, ids, names2)

      # merge elements of final_list into data frame
      df <- do.call(cbind.data.frame, final_list)
      # -> returns error, doesn't work!!



   }       
          )

df <- do.call(cbind.data.frame, src)  
# works fine outside function

mapply
始终简化，因此不太可能生成列表作为输出。您可以尝试使用
Map
，这不会简化。如果没有一个可复制的示例，就很难判断可能的错误。添加了xml代码以提供可复制的示例
<a name="node" >
<b>
 <c name="subnode1" >
  <choice name="1" id="125096778" />
  <choice name="2" id="125096782" />
  <choice name="3" id="125096786" />
 </c>

 <c name="subnode2" >
  <choice name="1" id="125097062" />
  <choice name="2" id="125097083" />
  <choice name="3" id="125096990" />
  <choice name="4" id="125097065" />
  <choice name="5" id="125096984" />
</c>

 <c name="subnode3” >
  <choice name="1" id="125097219" />
  <choice name="2" id="125097227" />
  <choice name="3" id="125097231" />
  <choice name="4" id="125097235" />
  <choice name="5" id="125097243" />
  <choice name="6" id="125097215" />
  <choice name="7" id="125097239" />
  <choice name="8" id="125097223" />
  <choice name="9" id="125097247" />
 </c>

 <c name="subnode4" >
  <choice name="1" id="125097251" />
  <choice name="2" id="125097259" />
  <choice name="3" id="125097255" />
 </c>

 <c name="subnode5" >
  <choice name="1" id="125097303" />
  <choice name="2" id="125097306" />
  <choice name="3" id="125097309" />
 </c>
</b>
</a>