I an attempt to run the following code to scrape the table titled "Advanced", whos id is also dictated as "advanced":
url <- paste0("https://www.basketball-reference.com/teams/GSW/2016.html")
webpage <- read_html(url)
col_names <- webpage %>%
html_nodes("table#advanced")
However, when I run this code and try to print col_names, I receive the following value: {xml_nodeset (0)}. How can I properly scrape my desired table?
Related
I am currently working a project to scrape the content of the Performance Characteristics table on this website
https://www.ishares.com/uk/individual/en/products/251795/ishares-ftse-100-ucits-etf-inc-fund
The data I am wanting to extract from this table is the 12 m trailing yield of 3.43%
The code I wrote to do this is:
url <- "https://www.ishares.com/uk/individual/en/products/251795/ishares-ftse-100-ucits-etf-inc-fund"
etf_Data <- url %>%
read_html() %>%
html_nodes(xpath='//*[#id="fundamentalsAndRisk"]/div') %>%
html_table()
etf_Data <- etf_Data[[1]]
which provided me with an empty list with the error message 'Error in etf_Data[[1]] : subscript out of bounds'
Using Google inspect I have tried various XPaths including reading it in html_text:
url <- "https://www.ishares.com/uk/individual/en/products/251795/ishares-ftse-100-ucits-etf-inc-fund"
etf_Data <- url %>%
read_html() %>%
html_nodes(xpath='//*[#id="fundamentalsAndRisk"]/div/div[4]/span[2]') %>%
html_text()
etf_Data <- etf_Data[[1]]
However with no success.
Having gone through other Stack Overflow responses I have not been able to solve my issue.
Would someone be able to assist.
Thank you
C
Couple of things:
There is a different URI you end up at in order to get the content you want. This comes when you manually accept certain conditions on the page
The data you want is not within a table
You can add a queryString with EntryPassthrough parameter = True to get to the right URI and then use :contains and an adjacent sibling combinator to get the desired value
library(rvest)
library(magrittr)
url <- "https://www.ishares.com/uk/individual/en/products/251795/ishares-ftse-100-ucits-etf-inc-fund?switchLocale=y&siteEntryPassthrough=true"
trailing_12m_yield <- url %>%
read_html() %>%
html_element('.caption:contains("12m Trailing Yield") + .data') %>% html_text2()
I'm trying to scrape the table for each subject:
This is the main link https://htmlaccess.louisville.edu/classSchedule/setupSearchClassSchedule.cfm?error=0 It looks like below:
I have to select each subject and click search, which takes to the link https://htmlaccess.louisville.edu/classSchedule/searchClassSchedule.cfm
Each subject gives a different table. For subject Accounting I tried to get the table like below: I used Selector Gadget Chrome extension to get the node string for html_nodes
library(rvest)
library(tidyr)
library(dplyr)
library(ggplot2)
url <- "https://htmlaccess.louisville.edu/classSchedule/searchClassSchedule.cfm"
df <- read_html(url)
tot <- df %>%
html_nodes('table+ table td') %>%
html_text()
But it didn't work:
## show
tot
character(0)
Is there a way to get the tables for each subject in a code with R?
Your problem is that the site requires a web form be submitted - that's what happens when you click the "Search" button on the page. Without submitting that form, you won't be able to access the data. This is evident if you attempt to navigate to the link you're trying to scrape - punch that into your favorite web browser and you'll see that there's no tables at all at "https://htmlaccess.louisville.edu/classSchedule/searchClassSchedule.cfm". No wonder nothing shows up!
Fortunately, you can submit web forms with R. It requires a little bit more code, however. My favorite package for this is httr, which partners nicely with rvest. Here's the code that will submit a form using httr and then proceed with the rest of your code.
library(rvest)
library(dplyr)
library(httr)
request_body <- list(
term="4212",
subject="ACCT",
catalognbr="",
session="none",
genEdCat="none",
writingReq="none",
comBaseCat="none",
sustainCat="none",
starttimedir="0",
starttimehour="08",
startTimeMinute="00",
endTimeDir="0",
endTimeHour="22",
endTimeMinute="00",
location="any",
classstatus="0",
Search="Search"
)
resp <- httr::POST(
url = paste0("https://htmlaccess.louisville.edu/class",
"Schedule/searchClassSchedule.cfm"),
encode = "form",
body = request_body)
httr::status_code(resp)
df <- httr::content(resp)
tot <- df %>%
html_nodes("table+ table td") %>%
html_text() %>%
matrix(ncol=17, byrow=TRUE)
On my machine, that returns a nicely formatted matrix with the expected data. Now, the challenge was figuring out what the heck to put in the request body. For this, I use Chrome's "inspect" tool (right click on a webpage, hit "inspect"). On the "Network" tab of that side panel, you can track what information is being sent by your browser. If I start on the main page and keep that side tab up while I "search" for accounting, I see that the top hit is "searchClassSchedule.cfm" and open that up by clicking on it. There, you can see all the form fields that were submitted to the server and I simply copied those over into R manually.
Your job will be to figure out what shortened name the rest of the departments use! "ACCT" seems to be the one for "Accounting". Once you've got those names in a vector you can loop over them with a for loop or lapply statement:
dept_abbrevs <- c("ACCT", "AIRS")
lapply(dept_abbrevs, function(abbrev){
...code from above...
...after defining message body...
message_body$subject <- abbrev
...rest of the code...
}
i'm using xpath and rvest for scraping an htm page. Other examples of rvest work well with pipelines, but for this particular script nothing is returned.
webpage <- read_html("https://www.sec.gov/litigation/admin/34-45135.htm")
whomst <- webpage %>% html_nodes(xpath = '/html/body/table[2]/tbody/tr/td[3]/font/p[1]/table/tbody/tr/td[1]/p[2]')
What is returned is :
{xml_nodeset (0)}
Here is a screenshot of the page and the corresponding html
And here's the page that I'm on: https://www.sec.gov/litigation/admin/34-45135.htm. I'm trying to extract the words, "PINNACLE HOLDINGS, INC."
Sometimes chrome tool doesn't give accurate xpath or css, you need to try by yourself, this selector works:
webpage %>% html_nodes("td > p:nth-child(3)") %>% html_text()
result:
[1] "PINNACLE HOLDINGS, INC., \n
I am currently trying to extract the URLs from the wikipedia page with a list of chief executive officers, the code then opens the URLs and copies the text into .txt files for me to use. the trouble is the allurls object only contains the later half of the URL. For example allurls[1] gives ""/wiki/Pierre_Nanterme"". Thus when I run this code
library("xml2")
library("rvest")
url <- "https://en.wikipedia.org/wiki/List_of_chief_executive_officers"
allurls <- url %>% read_html() %>% html_nodes("td:nth-child(2) a") %>%
html_attr("href") %>%
.[!duplicated(.)]%>%lapply(function(x)
read_html(x)%>%html_nodes("body"))%>%
Map(function(x,y)
write_html(x,tempfile(y,fileext=".txt"),options="format"),.,
c(paste("tmp",1:length(.))))
allurls[1]
I get the following error:
Error: '/wiki/Pierre_Nanterme' does not exist.
I have this website which has a table of many pages. Can someone help me read all pages of that table into R?
Website:
https://www.fdic.gov/bank/individual/failed/banklist.html
You can scrape the entire HTML table using the rvest package. See the code below. The code automatically identifies the entire table and reads in all 555 entries.
require(rvest)
URL <- "https://www.fdic.gov/bank/individual/failed/banklist.html"
failed_banks <- URL %>%
read_html() %>%
html_table() %>%
as.data.frame()