Nonexistent database raises FileNotFoundError

[radekholy24]

Can you please take a look at this:

Reproducer

1. make sure that nonexistent.mmdb does not exist
2. call geoip2.database.Reader('nonexistent.mmdb')

Actual result

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/tmp/venv/lib/python3.5/site-packages/geoip2/database.py", line 82, in __init__
    self._db_reader = maxminddb.open_database(filename, mode)
  File "/tmp/venv/lib/python3.5/site-packages/maxminddb/__init__.py", line 32, in open_database
    return maxminddb.extension.Reader(database)
FileNotFoundError: No such file or directory: 'nonexistent.mmdb'

Expected result

A ValueError or a change in the documentation.

Versions

geoip2 2.4.2
maxminddb 1.2.3
libmaxminddb-dev 1.0.4-2.1
libmaxminddb0 1.0.4-2.1
Python 3.5.2
Ubuntu 16.04.1

[oschwald]

Thanks. The documentation should probably be updated in this case as FileNotFoundError seems like the appropriate exception.