dogs.py

from bs4 import BeautifulSoup
from requests import Session
import csv


def ref(head):
    return '%s%d' % (chr(ord('A') + theads.index(head)), irow)

sess = Session()
theads = ('Breed Name', 'Tested', 'Passed', 'Failed', 'Percent')

with open('dogs.csv', 'w', newline='') as f:
    tab = csv.DictWriter(f, fieldnames=theads)
    tab.writeheader()
    irow = 2
    for page in range(1, 9):
        resp = sess.get('http://atts.org/breed-statistics/statistics-page%d' % page)
        bs = BeautifulSoup(resp.text, 'html.parser')
        heads = [s.text for s in bs.find('tr').find_all('span')]
        for row in bs.find_all('tr')[1:]:
            cells = [s.text for s in row.find_all('strong')]
            if cells[heads.index('Breed Name')] == 'TOTALS':  exit()
            trow = {h: cells[heads.index(h)]
                    for h in ('Breed Name', 'Passed', 'Failed')}
            trow.update({'Tested': '=%s+%s' % (ref('Passed'), ref('Failed')),
                         'Percent': '=%s/%s' % (ref('Passed'), ref('Tested'))})
            tab.writerow(trow)
            irow += 1