How can I extract values from Tableau dashboard

Question

I am trying to extract the "Company & Tests" values from this Web page: https://public.tableau.com/views/v_7_14_2020/COVID-19TestingCommons

The preferred output would be a array with company and number of tests for each company.

There is another thread (How can I scrape tooltips value from a Tableau graph embedded in a webpage) with a similar question..

I tried to work with that and it didn't work in my case

Thank You.

import requests 
from bs4 import BeautifulSoup
import json
import time

data_host = "https://public.tableau.com"

r = requests.get(
    f"{data_host}/views/v_7_14_2020/COVID-19TestingCommons",
    params= {
        ":showVizHome":"no",
    }
)
soup = BeautifulSoup(r.text, "html.parser")

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

dataUrl = f'{data_host}{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"])

Answer 1

Your tableau address is using server side rendering in this situation. It means that no data is supplied to the browser by default, and the server renders visuals with the data (tables, maps, etc.). Selection events are triggered by JS sending mouse coordinates to the server.

However, utilising the filters, you can have some info rendered client-side in your situation. When you choose a filter, such as "specimen," the data is rendered on the client (actual data are sent to the browser).

To extract data from Tableau workbooks, I created a tableau scraper library. You may run the following code to import the tableau data (empty worksheets), get the filter in the Diagnostic Target called Specimen worksheet, and save it. Get the worksheet data for each of these by collecting and iterating each value of this filter:

from tableauscraper import TableauScraper as TS
import pandas as pd

url = "https://public.tableau.com/views/v_7_14_2020/COVID-19TestingCommons"

ts = TS()
ts.loads(url)
workbook = ts.getWorkbook()

ws = workbook.getWorksheet("Diagnostic Target")

specimens = [
    t["values"]
    for t in ws.getFilters()
    if t["column"] == "Specimen Collected"
][0]

pdList = []
for specimen in specimens:
    print(f"specimen: {specimen}")
    specResultWb = ws.setFilter("Specimen Collected", specimen)
    df = specResultWb.getWorksheet("Company and Tests").data
    pdList.append(df)

result = pd.concat(pdList, ignore_index=True)
print(result)

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