Python pip install如何修改默认下载路径

C:\Users\hewei>python -m site
sys.path = [
  'C:\\Users\\xxx',
  'D:\\Program Files\\Python37\\python37.zip',
  'D:\\Program Files\\Python37\\DLLs',
  'D:\\Program Files\\Python37\\lib',
  'D:\\Program Files\\Python37',
  'D:\\Program Files\\Python37\\lib\\site-packages',
]
USER_BASE: 'C:\\Users\\xxx\\AppData\\Roaming\\Python' (doesn't exist)
USER_SITE: 'C:\\Users\\xxx\\AppData\\Roaming\\Python\\Python37\\site-packages' (doesn't exist)
ENABLE_USER_SITE: True