r - R 从 Yahoo Finance 抓取 HTML 表

Question

我想从雅虎财经中抓取一张表格并将其下载为数据框。不幸的是，我真的不知道如何使用rvest-package 来做到这一点。

这是第一种方法：

library(tidyverse)
library(rvest)

url<-"https://finance.yahoo.com/calendar/ipo?from=2021-02-21&to=2021-02-27&day=2021-02-23"

url %>%
  html() %>%
  html_nodes(xpath="table") %>%
  html_table()

正如预期的那样，代码不起作用。有人能帮我吗？

我想将框架表作为数据框：

提前谢谢了！

标签： rweb-scrapingrvest

Answer 1

不幸的是，使用html_table. 这是一种从表中提取单个值并进行一些后处理以获取数据框中的数据的方法。

library(rvest)

url<-"https://finance.yahoo.com/calendar/ipo?from=2021-02-21&to=2021-02-27&day=2021-02-23"

url %>%
  read_html() %>%
  html_nodes('table') %>%
  .[[1]] -> tab1
header <- tab1 %>% html_nodes('th') %>% html_text()

result <- tab1%>%
  html_nodes('tr.simpTblRow td') %>%
  html_text() %>%
  matrix(ncol = 9, byrow = TRUE) %>%
  as.data.frame()
names(result) <- header

result

#    Symbol                                     Company Exchange
#1    VELOU            Velocity Acquisition Corp. Units   Nasdaq
#2    FTAAU          FTAC Athena Acquisition Corp. Unit   Nasdaq
#3    CMIIU               CM Life Sciences II Inc. Unit   Nasdaq
#4                                       Metropress Ltd      LSE
#5 CTWO.P.V                        County Capital 2 Ltd     TSXV
#6    GSEVU              Gores Holdings VII, Inc. Units   Nasdaq
#7     NVOS Novo Integrated Sciences, Inc. Common Stock   Nasdaq
#8    SLAMU                             Slam Corp. Unit   Nasdaq

#          Date   Price Range Price Currency   Shares  Actions
#1 Feb 23, 2021 10.00 - 10.00     -      USD        - Expected
#2 Feb 23, 2021             -     -      USD        - Expected
#3 Feb 23, 2021 10.00 - 10.00     -      USD        - Expected
#4 Feb 01, 2021             -     6      GBP 45452752   Priced
#5 Nov 19, 2020   0.08 - 0.08   0.1      CAD  6000000   Priced
#6 Feb 23, 2021             -     -      USD        - Expected
#7 Feb 23, 2021             -     -      USD        - Expected
#8 Feb 23, 2021 10.00 - 10.00     -      USD        - Expected