(...) is not a length 1 atomic vector 错误

Question

I am trying to scrape IMDB data, and for one variable I keep getting an error.

Error: Result 28 is not a length 1 atomic vector

library(rvest)
library(purrr)
library(tidyr)

topmovies <- read_html("http://www.imdb.com/chart/top")
links <- topmovies %>%
  html_nodes(".titleColumn") %>%
  html_nodes("a") %>%
  html_attr("href") %>% 
  xml2::url_absolute("http://imdb.com")

pages <- links %>% map(read_html)

budget <- try(pages %>%
  map_chr(. %>%
            html_nodes("#titleDetails .txt-block:nth-child(11)") %>%
            html_text() %>%
            #gsub("\\D", "", .) %>%
            extract_numeric()),silent=TRUE)

When I do it with try (as in the code), I get

budget

[1] "Error: cannot convert object to a data frame\n" attr(,"class") [1] "try-error" attr(,"condition") <Rcpp::exception: cannot convert object to a data frame>

It would be great if anyone could tell me what is going wrong / why try isn't just skipping that result?

Answer 1

This can happen when you encounter NULL . Try:

map_if(is_empty, ~ NA_character_)

in the pipe chain and see if it works.