How can I scrape tooltips value from a Tableau graph embedded in a webpage

Edit

I’ve made a python library to scrape tableau dashboard. The implementation is more straightforward :

from tableauscraper import TableauScraper as TS

url = "https://public.tableau.com/views/Colorado_COVID19_Data/CO_Home"

ts = TS()
ts.loads(url)
dashboard = ts.getDashboard()

for t in dashboard.worksheets:
    #show worksheet name
    print(f"WORKSHEET NAME : {t.name}")
    #show dataframe for this worksheet
    print(t.data)

run this on repl.it

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Old answer

The graphic seems to be generated in JS from the result of an API which looks like :

POST https://public.tableau.com/TITLE/bootstrapSession/sessions/SESSION_ID 

The SESSION_ID parameter is located (among other things) in tsConfigContainer textarea in the URL used to build the iframe.

Starting from https://covid19.colorado.gov/hospital-data :

• check element with class tableauPlaceholder
• get the param element with attribute name
• it gives you the url : https://public.tableau.com/views/{urlPath}
• the previous link gives you a textarea with id tsConfigContainer with a bunch of json values
• extract the session_id and root path (vizql_root)
• make a POST on https://public.tableau.com/ROOT_PATH/bootstrapSession/sessions/SESSION_ID with the sheetId as form data
• extract the json from the result (result is not json)

Code :

import requests
from bs4 import BeautifulSoup
import json
import re

r = requests.get("https://covid19.colorado.gov/hospital-data")
soup = BeautifulSoup(r.text, "html.parser")

# get the second tableau link
tableauContainer = soup.findAll("div", { "class": "tableauPlaceholder"})[1]
urlPath = tableauContainer.find("param", { "name": "name"})["value"]

r = requests.get(
    f"https://public.tableau.com/views/{urlPath}",
    params= {
        ":showVizHome":"no",
    }
)
soup = BeautifulSoup(r.text, "html.parser")

tableauData = json.loads(soup.find("textarea",{"id": "tsConfigContainer"}).text)

dataUrl = f'https://public.tableau.com{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))

print(data["secondaryInfo"]["presModelMap"]["dataDictionary"]["presModelHolder"]["genDataDictionaryPresModel"]["dataSegments"]["0"]["dataColumns"])

From there you have all the data. You will need to look for the way the data is splitted as it seems all the data is dumped through a single list. Probably looking at the other fields in the JSON object would be useful for that.