How to use the geoip2.__version__ function in geoip2

import codecs
import os
import sys

import geoip2

from setuptools import setup

packages = ['geoip2']

requirements = [i.strip() for i in open("requirements.txt").readlines()]

setup(
    name='geoip2',
    version=geoip2.__version__,
    description='MaxMind GeoIP2 API',
    long_description=codecs.open('README.rst', 'r', 'utf-8').read(),
    author='Gregory Oschwald',
    author_email='goschwald@maxmind.com',
    url='http://www.maxmind.com/',
    packages=['geoip2'],
    package_data={'': ['LICENSE']},
    package_dir={'geoip2': 'geoip2'},
    include_package_data=True,
    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*',
    install_requires=requirements,
    extras_require={':python_version=="2.7"': ['ipaddress']},
    tests_require=['requests_mock>=0.5'],
    test_suite="tests",
    license=geoip2.__license__,
    classifiers=[

# The encoding of source files.
#source_encoding = 'utf-8-sig'

# The master toctree document.
master_doc = 'index'

# General information about the project.
project = 'geoip2'
copyright = '2013-2019, MaxMind, Inc.'

# The version info for the project you're documenting, acts as replacement for
# |version| and |release|, also used in various other places throughout the
# built documents.
#
# The short X.Y version.
version = geoip2.__version__
# The full version, including alpha/beta/rc tags.
release = geoip2.__version__

# The language for content autogenerated by Sphinx. Refer to documentation
# for a list of supported languages.
#language = None

# There are two options for replacing |today|: either, you set today to some
# non-false value, then it is used:
#today = ''
# Else, today_fmt is used as the format for a strftime call.
#today_fmt = '%B %d, %Y'

# List of patterns, relative to source directory, that match files and
# directories to ignore when looking for source files.
exclude_patterns = ['_build']

def _user_agent(self):
        return 'GeoIP2 Python Client v%s (%s)' % (geoip2.__version__,
                                                  default_user_agent())

# The master toctree document.
master_doc = 'index'

# General information about the project.
project = 'geoip2'
copyright = '2013-2019, MaxMind, Inc.'

# The version info for the project you're documenting, acts as replacement for
# |version| and |release|, also used in various other places throughout the
# built documents.
#
# The short X.Y version.
version = geoip2.__version__
# The full version, including alpha/beta/rc tags.
release = geoip2.__version__

# The language for content autogenerated by Sphinx. Refer to documentation
# for a list of supported languages.
#language = None

# There are two options for replacing |today|: either, you set today to some
# non-false value, then it is used:
#today = ''
# Else, today_fmt is used as the format for a strftime call.
#today_fmt = '%B %d, %Y'

# List of patterns, relative to source directory, that match files and
# directories to ignore when looking for source files.
exclude_patterns = ['_build']

# The reST default role (used for this markup: `text`) to use for all documents.