example

In [8]: import re
   ...: import subprocess
   ...: def get_ext_info(dev):
   ...:     try:
   ...:         output = subprocess.check_output(['sudo', 'dumpe2fs', '-h', dev], stderr=subprocess.DEVNULL).decode()
   ...:     except:
   ...:         pass
   ...:     data = dict()
   ...:     for line in output.splitlines():
   ...:         if m := re.match(r'^([^:]+):\s+(.+)$', line):
   ...:             data[m.group(1)] = m.group(2)
   ...:     return data
   ...: 
   ...: get_ext_info("/dev/sda1")["Reserved GDT blocks"]
Out[8]: '1010'