Thanks for explaining. Indeed range appears in __builtins__. It is a surprise to type range and get <class 'range'> in response. sum otoh gives <built-in function sum>. The distinction between function, type and class seems muddy.

When I enter "range" in the index box in the windows documentation display I am offered: 

(1)built-in function, which takes me to the paragraph that started this issue. It does NOT take me to the built-in functions topic, whereas sum does.

(2) object, and range (built-in class)which take me to the built-in types topic. This seems to add to the confusion.