Count number of nodes R, xml2

April 19, 2022

I have an xml file and want to know the count of a specific node using R. My xml looks something like below. The node count should be 4. I’m using the xml2 package. Notice there’s another element, <tag>, at the same level that I don’t want to count.

I appreciate the help. Thanks!

<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>

>Solution :

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>
")