Nonebot2 nb-cli reported an error ImportError: cannot import name'main' from'pip' solution

Modify site-packages\nb_cli\handlers.py

try:
    from pip._internal.cli.main import main as pipmain
except ImportError:
    from pip import main as pipmain

before fixing

try:
    from pip._internal.cli.main import main as pipmain
except ImportError:
    from pip._internal import main as pipmain

After modification