安装完txt2hpo包后，按照包的介绍文档简单调用，出现错误：TypeError: expected str, bytes or os.PathLike object, not NoneType
txt2hpo是一个第三方python库，用于识别文本中的hpo表型术语。我使用pip将其安装在conda创建的虚拟环境下，并在pycharm中使用所创建虚拟环境的python.exe编译。
根据官方介绍文档调用txt2hpo：
from txt2hpo.extract import Extractor
extract = Extractor()
result = extract.hpo("patient with developmental delay and hypotonia")
报错信息如下：
Traceback (most recent call last):
File "D:/PPD/2hpo.py", line 2, in <module>
from txt2hpo.extract import Extractor
File "D:\ProgramData\Anaconda3\envs\python36\lib\site-packages\txt2hpo\extract.py", line 7, in <module>
from txt2hpo.build_tree import update_progress, hpo_network
File "D:\ProgramData\Anaconda3\envs\python36\lib\site-packages\txt2hpo\build_tree.py", line 4, in <module>
from txt2hpo.config import logger, config
File "D:\ProgramData\Anaconda3\envs\python36\lib\site-packages\txt2hpo\config.py", line 29, in <module>
config_directory = os.path.join(os.environ.get('HOME'), f'.{__project__}')
File "D:\ProgramData\Anaconda3\envs\python36\lib\ntpath.py", line 76, in join
path = os.fspath(path)
TypeError: expected str, bytes or os.PathLike object, not NoneType
看起来官方文档中的代码与路径无关，为什么会这样报错呢？请问有什么可能的解决方法吗？
