html_table 不适用于长行 [英] html_table dont work with long row

问题描述

我正在尝试提取页面上的表格

I am trying to extract the table that is on the page

使用 html_table 和 rvest，但是第一行的第一个文本是表格的一部分，显然会导致与 html_table 的冲突.我留下代码

Using html_table and rvest, However the first text, first row, is part of the table and apparently is causing conflicts with html_table. I leave the code

#Library's
library(rvest)
library(XML)

    url<-"http://www.svs.cl/institucional/mercados/consulta.php?mercado=V&Estado=VI&entidad=RVEMI" #page
    url<-read_html(url) 
    table<-html_nodes(url,"table") #read notes
    table<-html_table(table,fill=TRUE) #write like table

而错误是

if (length(p) > 1 & maxp * n != sum(unlist(nrows)) & maxp * n 中的错误!= :需要 TRUE/FALSE 的缺失值另外:警告消息:在 lapply(ncols, as.integer) 中:强制引入的 NAs

Error in if (length(p) > 1 & maxp * n != sum(unlist(nrows)) & maxp * n != : missing value where TRUE/FALSE needed In addition: Warning message: In lapply(ncols, as.integer) : NAs introduced by coercion

也许可以使用 html_text 编写，但我需要表格格式.

Maybe it could be written using html_text, but I need it in table format.

感谢任何帮助

推荐答案

这不是表格的大小，而是前两行中极其粗糙的节点.

It's not the size of the table but the extremely gnarly nodes in the first two rows.

所以，只需编辑出问题节点.

So, just edit out the problem nodes.

xml2 支持更广泛的 libxml2 操作，现在:

xml2 supports a much wider array of libxml2 operations, now:

library(rvest)
library(tidyverse)

pg <- read_html("http://www.svs.cl/institucional/mercados/consulta.php?mercado=V&Estado=VI&entidad=RVEMI")

xml_remove(html_nodes(pg, xpath=".//table/tr[1]"))
xml_remove(html_nodes(pg, xpath=".//table/tr[1]"))

html_nodes(pg, xpath=".//table") %>% 
  html_table() %>% 
  .[[1]] %>% 
  as_tibble()

## # A tibble: 368 × 3
##            X1                                                   X2    X3
##         <chr>                                                <chr> <chr>
## 1  76675290-K                                       AD RETAIL S.A.    VI
## 2  98000000-1  ADMINISTRADORA  DE FONDOS DE PENSIONES CAPITAL S.A.    VI
## 3  98000100-8  ADMINISTRADORA  DE FONDOS DE PENSIONES HABITAT S.A.    VI
## 4  76240079-0    ADMINISTRADORA DE FONDOS DE PENSIONES CUPRUM S.A.    VI
## 5  76762250-3    ADMINISTRADORA DE FONDOS DE PENSIONES MODELO S.A.    VI
## 6  98001200-K ADMINISTRADORA DE FONDOS DE PENSIONES PLANVITAL S.A.    VI
## 7  76265736-8   ADMINISTRADORA DE FONDOS DE PENSIONES PROVIDA S.A.    VI
## 8  94272000-9                                       AES GENER S.A.    VI
## 9  96566940-K                            AGENCIAS UNIVERSALES S.A.    VI
## 10 91253000-0                        AGRICOLA NACIONAL S.A.C. E I.    VI
## # ... with 358 more rows

注意你可以这样做:

xml_remove(html_nodes(pg, xpath=".//table/tr[position() >= 1 and position() <=2]"))

而不是两个删除操作，但它几乎同样冗长，这里没有真正的性能提升.

instead of the two remove ops but it's almost as verbose and there's no real performance gain here.

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