pytest 报错 ImportError: cannot import name 'main'

求助各位大神，搞不定了

执行pytest一直报错

C:\Users\Administrator>pytest
Traceback (most recent call last):
File "c:\users\administrator\appdata\local\programs\python\python36\lib\runpy.py", line 193, in _r
un_module_as_main
"__main__", mod_spec)
File "c:\users\administrator\appdata\local\programs\python\python36\lib\runpy.py", line 85, in _ru
n_code
exec(code, run_globals)
File "C:\Users\Administrator\AppData\Local\Programs\Python\Python36\Scripts\pytest.exe\__main__.py
", line 4, in <module>
ImportError: cannot import name 'main'