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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_long_description():
 """Get PyPI long description from the .rst file."""

    pkg_dir = get_package_dir()
    with open(os.path.join(pkg_dir, '.pypi_long_desc.rst')) as readme_file:
        long_description = readme_file.read()
    return long_description