TypeError: a bytes-like object is required, not 'str'

python-geoip (1.2)
python 3.6.9
Reproduce:

from geoip import geolite2
match = geolite2.lookup('8.8.8.8')

Output:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.6/dist-packages/geoip.py", line 364, in lookup
    return self._get_actual_db().lookup(ip_addr)
  File "/usr/local/lib/python3.6/dist-packages/geoip.py", line 350, in _get_actual_db
    rv = self._load_database()
  File "/usr/local/lib/python3.6/dist-packages/geoip.py", line 342, in _load_database
    return mod.loader(self, sys.modules[__name__])
  File "/usr/local/lib/python3.6/dist-packages/_geoip_geolite2/__init__.py", line 9, in loader
    return mod.open_database(filename)
  File "/usr/local/lib/python3.6/dist-packages/geoip.py", line 508, in open_database
    md = _read_mmdb_metadata(buf)
  File "/usr/local/lib/python3.6/dist-packages/geoip.py", line 382, in _read_mmdb_metadata
    buf.size() - MMDB_METADATA_BLOCK_MAX_SIZE)
TypeError: a bytes-like object is required, not 'str'

The same issue happens using a self-provided latest DB:

from geoip import open_database
db = open_database('GeoLite2-City.mmdb')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.6/dist-packages/geoip.py", line 508, in open_database
    md = _read_mmdb_metadata(buf)
  File "/usr/local/lib/python3.6/dist-packages/geoip.py", line 382, in _read_mmdb_metadata
    buf.size() - MMDB_METADATA_BLOCK_MAX_SIZE)
TypeError: a bytes-like object is required, not 'str'

Start with geoip.py, especially open_database and _read_mmdb_metadata, then reproduce the failure with geolite2.lookup('8.8.8.8') and open_database('GeoLite2-City.mmdb') under Python 3.6. Done means both database-loading paths complete without the reported bytes-versus-string TypeError.