我正在使用 miniconda 版本的 python，并使用 virtualenv 命令创建虚拟环境。最初 pip install 命令工作正常，但一段时间后它开始给我 ModuleNotFoundError当我调用安装 jupyter 笔记本的命令时。pip install jupyter我也尝试过pip3 install jupyter甚至pip list命令也不起作用。我得到的错误是Traceback (most recent call last):  File "/Users/aarsh/Code/p/bin/pip", line 8, in <module>    sys.exit(main())  File "/Users/aarsh/Code/p/lib/python3.8/site-packages/pip/_internal/cli/main.py", line 73, in main    command = create_command(cmd_name, isolated=("--isolated" in cmd_args))  File "/Users/aarsh/Code/p/lib/python3.8/site-packages/pip/_internal/commands/__init__.py", line 104, in create_command    module = importlib.import_module(module_path)  File "/Users/aarsh/opt/miniconda3/lib/python3.8/importlib/__init__.py", line 127, in import_module    return _bootstrap._gcd_import(name[level:], package, level)  File "<frozen importlib._bootstrap>", line 1014, in _gcd_import  File "<frozen importlib._bootstrap>", line 991, in _find_and_load  File "<frozen importlib._bootstrap>", line 975, in _find_and_load_unlocked  File "<frozen importlib._bootstrap>", line 671, in _load_unlocked  File "<frozen importlib._bootstrap_external>", line 783, in exec_module  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed请帮我解决这个问题。