将 tableauViz 抓取到 R 数据帧中 [英] Web Scraping a tableauViz into an R dataframe
问题描述
我花了很多时间寻找这个问题的答案，但还没有找到任何东西.我想要完成的是抓取包含在 tableauViz 元素中的 Tableau 表信息并将其传播到 R 数据帧中.在我的第一次尝试中，使用 RStudio，我使用了以下代码并尝试将 tableauViz 读取为 HTML
I have spent a lot of time searching for an answer to this, but have not found anything yet. What I am trying to accomplish is to scrape Tableau table information that is contained in a tableauViz element and propagate it into an R dataframe. In my first attempt, using RStudio, I employed the following code and tried to read the tableauViz as HTML
# Load rvest functions
library(rvest)
# Specifying the url for desired website to be scrapped
url <- "https://oir.uga.edu/factbook/studentinformation/S07StuP58/"
# Reading the HTML code from the website
webpage <- read_html(url)
# Using CSS selectors to scrap the rankings section
rank_data_html <- html_nodes(webpage,'.tableauViz')
输出被格式化为 xml_nodeset 列表，如下所示.
The output was formatted as an xml_nodeset list as follows.
[[1]]
[[1]][[1]]
[1] "\n "
[[1]]$param
list()
attr(,"name")
[1] "host_url"
attr(,"value")
[1] "https%3A%2F%2Fpublic.tableau.com%2F"
[[1]]$param
list()
attr(,"name")
[1] "site_root"
attr(,"value")
[1] ""
[[1]]$param
list()
attr(,"name")
[1] "name"
attr(,"value")
[1] "S07StuP58/Dashboard1"
[[1]]$param
list()
attr(,"name")
[1] "tabs"
attr(,"value")
[1] "no"
[[1]]$param
list()
attr(,"name")
[1] "toolbar"
attr(,"value")
[1] "yes"
[[1]]$param
list()
attr(,"name")
[1] "static_image"
attr(,"value")
[1] "https://public.tableau.com/static/images/S0/S07StuP58/Dashboard1/1.png"
[[1]]$param
list()
attr(,"name")
[1] "animate_transition"
attr(,"value")
[1] "yes"
[[1]]$param
list()
attr(,"name")
[1] "display_static_image"
attr(,"value")
[1] "yes"
[[1]]$param
list()
attr(,"name")
[1] "display_spinner"
attr(,"value")
[1] "yes"
[[1]]$param
list()
attr(,"name")
[1] "display_overlay"
attr(,"value")
[1] "yes"
[[1]]$param
list()
attr(,"name")
[1] "display_count"
attr(,"value")
[1] "yes"
[[1]]$param
list()
attr(,"name")
[1] "filter"
attr(,"value")
[1] "publish=yes"
attr(,".class")
[1] "tableauViz"
attr(,"style")
[1] "display:none;"
我发现该列表中唯一有价值的属性是静态图像 png 链接.
The only attribute from that list that I found of value was the static image png link.
但是，我不相信我能够将其中任何一个转换为数据帧.
However, I don’t believe I’ll be able to convert any of that into a dataframe.
对这个问题的唯一参考是这个优秀的 YouTube 视频通过 R Notebooks 和 Shiny 将 Tableau 与 R 集成".我导航到作者的 GitHub 站点 以查看是否可以找到一些示例代码，但我找不到找到任何.
The only reference to this issue was this excellent YouTube Video "Integrating Tableau with R through R Notebooks and Shiny". I navigated to the author’s GitHub site to see if I could find some sample code but I was unable to locate any.
我该如何解决这个问题?
How do I resolve this issue?
推荐答案
为了获取数据，您需要在本例中为 tableau URL :
In order to get the data, you need the tableau URL which is in this case :
https://public.tableau.com/views/S07StuP58/Dashboard1?:embed=y&:showVizHome=no
流程如下:
调用以下网址:
call the following url :
GET https://public.tableau.com/views/S07StuP58/Dashboard1?:embed=y&:showVizHome=no
从 textarea 中提取 JSON 内容，id 为 tsConfigContainer
extract the JSON content from the textarea with id tsConfigContainer
使用 session_id 构建 url
build the url with the session_id
POST https://public.tableau.com/{vizql_path}/bootstrapSession/sessions/{session_id}
从原本不是 JSON 的响应中提取 JSON 数据(正则表达式来拆分数据)
extract the JSON data from the response which is not JSON originally (regex to split the data)
从大型 JSON 配置中提取数据，这并不简单，因为所有字符串数据都位于单个数组中.您需要从各个字段获取数据索引，以便能够将数据拆分为列，然后构建您的数据框
extract the data from the large JSON configuration, this is not straightforward since all the strings data are located in a single array. You need to get the data indices from various fields in order to be able to split the data into columns and then build your dataframe
以下代码将提示用户选择工作表(按索引)，解析数据并将其放入数据框中:
The following code will prompt the user to choose a worksheet (by index), parse the data and put it in a dataframe :
library(rvest)
library(rjson)
library(httr)
library(stringr)
#replace the hostname and the path if necessary
host_url <- "https://public.tableau.com"
path <- "/views/S07StuP58/Dashboard1"
body <- read_html(modify_url(host_url,
path = path,
query = list(":embed" = "y",":showVizHome" = "no")
))
data <- body %>%
html_nodes("textarea#tsConfigContainer") %>%
html_text()
json <- fromJSON(data)
url <- modify_url(host_url, path = paste(json$vizql_root, "/bootstrapSession/sessions/", json$sessionid, sep =""))
resp <- POST(url, body = list(sheet_id = json$sheetId), encode = "form")
data <- content(resp, "text")
extract <- str_match(data, "\\d+;(\\{.*\\})\\d+;(\\{.*\\})")
info <- fromJSON(extract[1,1])
data <- fromJSON(extract[1,3])
worksheets = names(data$secondaryInfo$presModelMap$vizData$presModelHolder$genPresModelMapPresModel$presModelMap)
for(i in 1:length(worksheets)){
print(paste("[",i,"] ",worksheets[i], sep=""))
}
selected <- readline(prompt="select worksheet by index: ");
worksheet <- worksheets[as.integer(selected)]
print(paste("you selected :", worksheet, sep=" "))
columnsData <- data$secondaryInfo$presModelMap$vizData$presModelHolder$genPresModelMapPresModel$presModelMap[[worksheet]]$presModelHolder$genVizDataPresModel$paneColumnsData
i <- 1
result <- list();
for(t in columnsData$vizDataColumns){
if (is.null(t[["fieldCaption"]]) == FALSE) {
paneIndex <- t$paneIndices
columnIndex <- t$columnIndices
if (length(t$paneIndices) > 1){
paneIndex <- t$paneIndices[1]
}
if (length(t$columnIndices) > 1){
columnIndex <- t$columnIndices[1]
}
result[[i]] <- list(
fieldCaption = t[["fieldCaption"]],
valueIndices = columnsData$paneColumnsList[[paneIndex + 1]]$vizPaneColumns[[columnIndex + 1]]$valueIndices,
aliasIndices = columnsData$paneColumnsList[[paneIndex + 1]]$vizPaneColumns[[columnIndex + 1]]$aliasIndices,
dataType = t[["dataType"]],
stringsAsFactors = FALSE
)
i <- i + 1
}
}
dataFull = data$secondaryInfo$presModelMap$dataDictionary$presModelHolder$genDataDictionaryPresModel$dataSegments[["0"]]$dataColumns
cstring <- list();
for(t in dataFull) {
if(t$dataType == "cstring"){
cstring <- t
break
}
}
data_index <- 1
name_index <- 1
frameData <- list()
frameNames <- c()
for(t in dataFull) {
for(index in result) {
if (t$dataType == index["dataType"]){
if (length(index$valueIndices) > 0) {
j <- 1
vector <- character(length(index$valueIndices))
for (it in index$valueIndices){
vector[j] <- t$dataValues[it+1]
j <- j + 1
}
frameData[[data_index]] <- vector
frameNames[[name_index]] <- paste(index$fieldCaption, "value", sep="-")
data_index <- data_index + 1
name_index <- name_index + 1
}
if (length(index$aliasIndices) > 0) {
j <- 1
vector <- character(length(index$aliasIndices))
for (it in index$aliasIndices){
if (it >= 0){
vector[j] <- t$dataValues[it+1]
} else {
vector[j] <- cstring$dataValues[abs(it)]
}
j <- j + 1
}
frameData[[data_index]] <- vector
frameNames[[name_index]] <- paste(index$fieldCaption, "alias", sep="-")
data_index <- data_index + 1
name_index <- name_index + 1
}
}
}
}
df <- NULL
lengthList <- c()
for(i in 1:length(frameNames)){
lengthList[i] <- length(frameData[[i]])
}
max <- max(lengthList)
for(i in 1:length(frameNames)){
if (length(frameData[[i]]) < max){
len <- length(frameData[[i]])
frameData[[i]][(len+1):max]<-""
}
df[frameNames[[i]]] <- frameData[i]
}
options(width = 1200)
df <- as.data.frame(df, stringsAsFactors = FALSE)
print(df)
给出以下输出:
X.Student.Aid.Program.Type..value X.Student.Aid.Program..value X..Measure.Names..alias X.Multiple.Values..alias
1 Grants/Scholarships Subtotal Graduate Amount Awarded $XXXXXXXX
2 Grants/Scholarships Other (External) Grants/Scholarships Graduate Amount Awarded $XXXXXX
3 Grants/Scholarships Miscellaneous Tuition/Fee Payments/Waivers Graduate Amount Awarded $XXXXXX
4 Grants/Scholarships Graduate Assistantship Tuition Waivers Graduate Amount Awarded $XXXXXX
5 Grants/Scholarships Athletic Scholarships Graduate Amount Awarded $XXXXXX
6 Grants/Scholarships Institutional Grants/Scholarships Graduate Amount Awarded $XXXXXX
7 Grants/Scholarships State (Other) Grants/Scholarships Graduate Amount Awarded $XXXXXX
8 Grants/Scholarships Zell Miller Scholarships Graduate Amount Awarded $XXXXXX
9 Grants/Scholarships HOPE Scholarships Graduate Amount Awarded $XXXXXX
10 Grants/Scholarships Federal (Other) Grants/Scholarships Graduate Amount Awarded
11 Grants/Scholarships Federal Supplemental Grants Graduate Amount Awarded
12 Grants/Scholarships Federal Pell Grants Graduate Amount Awarded
13 Grants/Scholarships Subtotal Graduate Number of Awards XXXXXX
14 Grants/Scholarships Other (External) Grants/Scholarships Graduate Number of Awards XXX
与上述代码等效的 python是:
The python equivalent of the code above would be :
import requests
from bs4 import BeautifulSoup
import json
import re
import pandas as pd
#replace the hostname and the path if necessary
host_url = "https://public.tableau.com"
path = "/views/S07StuP58/Dashboard1"
url = f"{host_url}{path}"
r = requests.get(
url,
params= {
":embed": "y",
":showVizHome": "no"
}
)
soup = BeautifulSoup(r.text, "html.parser")
tableauData = json.loads(soup.find("textarea",{"id": "tsConfigContainer"}).text)
dataUrl = f'{host_url}{tableauData["vizql_root"]}/bootstrapSession/sessions/{tableauData["sessionid"]}'
r = requests.post(dataUrl, data= {
"sheet_id": tableauData["sheetId"],
})
dataReg = re.search('\d+;({.*})\d+;({.*})', r.text, re.MULTILINE)
info = json.loads(dataReg.group(1))
data = json.loads(dataReg.group(2))
worksheets = list(data["secondaryInfo"]["presModelMap"]["vizData"]["presModelHolder"]["genPresModelMapPresModel"]["presModelMap"].keys())
for idx, ws in enumerate(worksheets):
print(f"[{idx}] {ws}")
selected = input("select worksheet by index: ")
worksheet = worksheets[int(selected)]
print(f"you selected : {worksheet}")
columnsData = data["secondaryInfo"]["presModelMap"]["vizData"]["presModelHolder"]["genPresModelMapPresModel"]["presModelMap"][worksheet]["presModelHolder"]["genVizDataPresModel"]["paneColumnsData"]
result = [
{
"fieldCaption": t.get("fieldCaption", ""),
"valueIndices": columnsData["paneColumnsList"][t["paneIndices"][0]]["vizPaneColumns"][t["columnIndices"][0]]["valueIndices"],
"aliasIndices": columnsData["paneColumnsList"][t["paneIndices"][0]]["vizPaneColumns"][t["columnIndices"][0]]["aliasIndices"],
"dataType": t.get("dataType"),
"paneIndices": t["paneIndices"][0],
"columnIndices": t["columnIndices"][0]
}
for t in columnsData["vizDataColumns"]
if t.get("fieldCaption")
]
dataFull = data["secondaryInfo"]["presModelMap"]["dataDictionary"]["presModelHolder"]["genDataDictionaryPresModel"]["dataSegments"]["0"]["dataColumns"]
def onAlias(it, value, cstring):
return value[it] if (it >= 0) else cstring["dataValues"][abs(it)-1]
frameData = {}
cstring = [t for t in dataFull if t["dataType"] == "cstring"][0]
for t in dataFull:
for index in result:
if (t["dataType"] == index["dataType"]):
if len(index["valueIndices"]) > 0:
frameData[f'{index["fieldCaption"]}-value'] = [t["dataValues"][abs(it)] for it in index["valueIndices"]]
if len(index["aliasIndices"]) > 0:
frameData[f'{index["fieldCaption"]}-alias'] = [onAlias(it, t["dataValues"], cstring) for it in index["aliasIndices"]]
df = pd.DataFrame.from_dict(frameData, orient='index').fillna(0).T
with pd.option_context('display.max_rows', None, 'display.max_columns', None, 'display.width', 1000):
print(df)
检查此 repo 以获取 Python 和 R 中的脚本
checkout this repo for both script in python and R
这篇关于将 tableauViz 抓取到 R 数据帧中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
