I am not really sure of this answer but I will just go ahead.
In Matlab for a function to work you should create same file name as the function name. when you call this function it searches for the file name and then executes the function. If the function is defined in the terminal itself then this method will not work. I am not sure how it happens in Python. This is more in the architecture level design. If you compare these two in this way it would be like comparing apple with an orange which is not a valid comparision
I would also make a note that Python is an open source and hence we can have out own libraries and install them. I Matlab the concept of library effectively means there is a *.m file and it searches in all its part.
