How to use the pygmt.__version__.split function in pygmt

"image_scrapers": (PyGMTScraper(),),
}

# Sphinx project configuration
templates_path = ["_templates"]
exclude_patterns = ["_build", "**.ipynb_checkpoints"]
source_suffix = ".rst"
# The encoding of source files.
source_encoding = "utf-8-sig"
master_doc = "index"

# General information about the project
year = datetime.date.today().year
project = "PyGMT"
copyright = "2017-{}, The PyGMT Developers.".format(year)
if len(__version__.split("+")) > 1 or __version__ == "unknown":
    version = "dev"
else:
    version = __version__

# These enable substitutions using |variable| in the rst files
rst_epilog = """
.. |year| replace:: {year}
""".format(
    year=year
)

html_last_updated_fmt = "%b %d, %Y"
html_title = "PyGMT"
html_short_title = "PyGMT"
html_logo = ""
html_favicon = "_static/favicon.png"