How to solve: AttributeError: 'FunctionInfo' object has no attribute 'fan_in' error in pydriller?

I am using pydriller to retrieve the commit information, but I have got an error 'AttributeError: 'FunctionInfo' object has no attribute 'fan_in'. Do you have any solution?

executing the code-

from pydriller import RepositoryMining

for commit in RepositoryMining (path_to_repo='https://github.com/openssl/openssl', only_commits=['9cedfc90cebc905b20275d534699a1070bba65a4']).traverse_commits():
    commit_row = {
        'hash': str(commit.hash),
        'msg': str(commit.msg),
        'author_date': str(commit.author_date),
        'merge': str(commit.merge),
        'dmm_unit_size': str(commit.dmm_unit_size)
    }
    print(commit_row)

I have got the following error output:-

Traceback (most recent call last):
  File "/Volumes/GoogleDrive/Shared drives/guru_shared/guru_research/CVE-code-extraction/Code/example_extraction.py", line 30, in <module>
    'dmm_unit_size': str(commit.dmm_unit_size)
  File "/usr/local/lib/python3.8/site-packages/pydriller/domain/commit.py", line 687, in dmm_unit_size
    return self._delta_maintainability(DMMProperty.UNIT_SIZE)
  File "/usr/local/lib/python3.8/site-packages/pydriller/domain/commit.py", line 735, in _delta_maintainability
    delta_profile = self._delta_risk_profile(dmm_prop)
  File "/usr/local/lib/python3.8/site-packages/pydriller/domain/commit.py", line 752, in _delta_risk_profile
    deltas = [mod._delta_risk_profile(dmm_prop) for mod in supported_modifications]
  File "/usr/local/lib/python3.8/site-packages/pydriller/domain/commit.py", line 752, in <listcomp>
    deltas = [mod._delta_risk_profile(dmm_prop) for mod in supported_modifications]
  File "/usr/local/lib/python3.8/site-packages/pydriller/domain/commit.py", line 386, in _delta_risk_profile
    low_before, high_before = self._risk_profile(self.methods_before, dmm_prop)
  File "/usr/local/lib/python3.8/site-packages/pydriller/domain/commit.py", line 336, in methods_before
    self._calculate_metrics(include_before=True)
  File "/usr/local/lib/python3.8/site-packages/pydriller/domain/commit.py", line 406, in _calculate_metrics
    self._function_list.append(Method(func))
  File "/usr/local/lib/python3.8/site-packages/pydriller/domain/commit.py", line 80, in __init__
    self.fan_in = func.fan_in
AttributeError: 'FunctionInfo' object has no attribute 'fan_in'

Solution

I found the reason for the problem and this is related to the issue with interpreter. The problem is solved after I changed the Python interpreter into version 3.8 in IDE.