purrr::map and xml2:: read_xml

Hi List, I am trying to extract the key words from 1403 papers in xml
format. I programmed such codes but they do not work but they only do
with the modification showed below. But that variation is not the one
I need because the 1403 xml files do not match to those in my folder.
Could you please tell me where are the mistakes in the codes list (A
or B) to help me to correct them? The data frame columns are an id and
the paths.

A-Does not work, but it is the one I need.

keyword <-
   muestra %>%
   select(path) %>%
   read_xmlmap(.f = function(x) { read_xml(x) %>%
        xml_find_all( ".//kwd") %>%
        xml_text(trim=T) })

B-It works but only with a small number of papers.

keyword <-
   muestra %>%
   select(path) %>%
    dplyr::sample_n(50) %>%
    unlist() %>%
   map(.f = function(x) { read_xml(x) %>%
        xml_find_all( ".//kwd") %>%
        xml_text(trim=T) })

Thank you,
Maicel Monzon MD, PHD


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