Einwohner.R

library(rvest)

fetchPopWiki = function(query) {
  tryCatch({
    city <- read_html(paste0("https://www.wikipedia.de/go?q=",gsub(" ","+",query),"&l=de"))
    table = city %>% html_nodes("table.infobox") %>%
      html_table(fill=TRUE)
    tds = city %>% html_nodes('th,td')
    population = sub('([\\.0-9]+).*', '\\1', html_text(tds[grep('Einwohner|Bevölkerung', tds)[1] + 1])) # manchmal Bevölkerung
    num = as.numeric(gsub('\\.','',population))
    return(num)
  }, error=function(e) return(NA))
}
fetchPopWiki = Vectorize(fetchPopWiki)

fetchPopWiki(c('Bad Saarow', 'Accra', 'Moskau', 'Doesnt exist'))