I think the command and error are explaining the issue (Can't clone)

:~$ git clone https://github.com/GoogleCloudPlatform/python-dev-samples/language/sentiment/
Cloning into 'sentiment'...
remote: Not Found
fatal: repository 'https://github.com/GoogleCloudPlatform/python-dev-samples/language/sentiment/' not found