Openpyxl hangs up when opening a particular xlsx

Created originally on Bitbucket by simoscofield (C. W.)

Here is the url for the file: https://www.edd.ca.gov/Jobs_and_Training/warn/WARN_Report.xlsx

from openpyxl import load_workbook

load_workbook('WARN_Report.xlsx') # hangs

This was initially reported by a pyexcel user on github (reference: https://github.com/pyexcel/pyexcel-xls/issues/34). After some diagnosis, it turns out openpyxl actually hangs up. I thought it may be of some interest for your project so I am opening an issue here.