我正在尝试上传图片，并想要获取上传图片的URL：
from google.colab import files
uploaded = files.upload()
for fn in uploaded.keys():
print('User uploaded file "{name}" with length {length} bytes'.format(
name=fn, length=len(uploaded[fn])))
是否有预定义的函数，或者我必须编写一个函数？