在 R 中使用 pdftools 在字符串后提取特定的 table

Question

我有几个 pdf，我想提取股东 table。如何指定仅提取字符串 'TWENTY LARGEST SHAREHOLDERS' 后出现的 table？

我试过了，但不太确定功能部分。

library("pdftools")
library("tidyverse")

url <- c("https://www.computershare.com/News/Annual%20Report%202019.pdf?2")

raw_text <- map(url, pdf_text)


clean_table <- function(table){
  table <- str_split(table, "\n", simplify = TRUE)
  table_start <- stringr::str_which(table, "TWENTY LARGEST SHAREHOLDERS")
  table <- table[1, (table_start +1 ):(table_end - 1)]
  table <- str_replace_all(table, "\s{2,}", "|")
  text_con <- textConnection(table)
  data_table <- read.csv(text_con, sep = "|")
  colnames(data_table) <- c("Name", "Number of Shares", "Percentage")
}

shares <- map_df(raw_text, clean_table)

Answer 1

试试这个。除了一些小问题外，主要的变化是我首先获得了包含所需 table 的页面。顺便说一句：您必须搜索“二十大股东”而不是“二十大股东”。

library(pdftools)
library(tidyverse)

# download pdf
url <- c("https://www.computershare.com/News/Annual%20Report%202019.pdf?2")

raw_text <- map(url, pdf_text)

clean_table1 <- function(raw) {
  
  # Split the single pages
  raw <- map(raw, ~ str_split(.x, "\n") %>% unlist())
  # Concatenate the splitted pages
  raw <- reduce(raw, c)
  
  table_start <- stringr::str_which(tolower(raw), "twenty largest shareholders")
  table_end <- stringr::str_which(tolower(raw), "total")
  table_end <- table_end[min(which(table_end > table_start))]
  
  table <- raw[(table_start + 3 ):(table_end - 1)]
  table <- str_replace_all(table, "\s{2,}", "|")
  text_con <- textConnection(table)
  data_table <- read.csv(text_con, sep = "|")
  colnames(data_table) <- c("Name", "Number of Shares", "Percentage")
  data_table
}

shares <- map_df(raw_text, clean_table1) 
head(shares)
#>                                                    Name Number of Shares
#> 1             J P Morgan Nominees Australia Pty Limited      109,500,852
#> 2                         Citicorp Nominees Pty Limited       57,714,777
#> 3                                       Mr Chris Morris       32,231,000
#> 4                             National Nominees Limited       19,355,892
#> 5                                         Welas Pty Ltd       18,950,000
#> 6 BNP Paribas Nominees Pty Ltd <Agency Lending DRP A/C>       11,520,882
#>   Percentage
#> 1      20.17
#> 2      10.63
#> 3       5.94
#> 4       3.56
#> 5       3.49
#> 6       2.12

在 R 中使用 pdftools 在字符串后提取特定的 table

Using pdftools in R to extract specific table after a string

r

text-mining

data-extraction

pdftools