How to use the exoplanet.__version__ function in exoplanet

# -*- coding: utf-8 -*-
import exoplanet
from packaging import version
import theano.tensor as tt
import numpy as np
from ..ops import autocompile


# NOTE: In version 0.1.7, DFM changed the coordinates
# so that the z-axis points TOWARD the observer!
if version.parse(exoplanet.__version__) > version.parse('0.1.7.dev0'):
    z_sign = 1
else:
    z_sign = -1


class KeplerianOrbit(exoplanet.orbits.KeplerianOrbit):
    """
    A wrapper around `exoplanet.orbits.KeplerianOrbit` that
    plays nice with `starry`. Refer to the docs of that class
    for all accepted keywords. In addition to those, this class
    accepts the following keyword arguments:

    Args:
        r_planet: The radius of the planet in ``R_sun``. Default is 
            the radius of the Earth.
        rot_period: The period of rotation of the planet in days.

warnings.filterwarnings("ignore", category=DeprecationWarning)
warnings.filterwarnings("ignore", category=FutureWarning)

# Hide Theano compilelock warnings
import logging
logger = logging.getLogger("theano.gof.compilelock")
logger.setLevel(logging.ERROR)

import theano
print("theano version: {0}".format(theano.__version__))

import pymc3
print("pymc3 version: {0}".format(pymc3.__version__))

import exoplanet
print("exoplanet version: {0}".format(exoplanet.__version__))

import starry
print("starry version: {0}".format(starry.__version__))

import logging

logger = logging.getLogger("theano.gof.compilelock")
logger.setLevel(logging.ERROR)

import theano

print("theano version: {0}".format(theano.__version__))

import pymc3

print("pymc3 version: {0}".format(pymc3.__version__))

import exoplanet

print("exoplanet version: {0}".format(exoplanet.__version__))

import logging

logger = logging.getLogger("theano.gof.compilelock")
logger.setLevel(logging.ERROR)

import theano

print("theano version: {0}".format(theano.__version__))

import pymc3

print("pymc3 version: {0}".format(pymc3.__version__))

import exoplanet

print("exoplanet version: {0}".format(exoplanet.__version__))

import matplotlib.pyplot as plt

plt.style.use("default")
plt.rcParams["savefig.dpi"] = 100
plt.rcParams["figure.dpi"] = 100
plt.rcParams["font.size"] = 16
plt.rcParams["font.family"] = "sans-serif"
plt.rcParams["font.sans-serif"] = ["Liberation Sans"]
plt.rcParams["mathtext.fontset"] = "custom"