节点数R，xml2

Question

我有一个xml文件，希望使用R知道特定节点的计数，我的xml如下所示。节点数应该是4，我使用的是xml2包。注意，还有另一个元素，<tag>，与我不想计算的级别相同。

我很感激你的帮助。谢谢!

<root>
  <node>
    <string>1</string>
    <string>2</string>
    <string>3</string>
    <string>4</string>
  </node>
  <node>
    <string>5</string>
    <string>6</string>
    <string>7</string>
    <string>8</string>
  </node>
  <node>
    <string>9</string>
    <string>10</string>
    <string>11</string>
    <string>12</string>
  </node>
  <node>
    <string>13</string>
    <string>14</string>
    <string>15</string>
    <string>16</string>
  </node>
  <tag>
    <string>17</string>
  </tag>
</root>

Answer 1

library(xml2)

length(xml2::xml_find_all(doc, ".//node"))
# [1] 4

doc <- read_xml("<root>
  <node>
    <string>1</string>
    <string>2</string>
    <string>3</string>
    <string>4</string>
  </node>
  <node>
    <string>5</string>
    <string>6</string>
    <string>7</string>
    <string>8</string>
  </node>
  <node>
    <string>9</string>
    <string>10</string>
    <string>11</string>
    <string>12</string>
  </node>
  <node>
    <string>13</string>
    <string>14</string>
    <string>15</string>
    <string>16</string>
  </node>
  <tag>
    <string>17</string>
  </tag>
</root>
")