How did the Keras Syntax changed over the time?

Hello,

I recently stumbled over a video tutorial with code examples. I tried to figure out what happens in the code, and did some research in the keras developer guides. I don’t have much experience with coding, but I think the syntax, which is used in my Code example is completely different from the syntax in the official keras docs…

My question would be if there was a significant change in the last years of writing python code with keras? And if the answer is yes, does it still make sense to work with the older syntax?