1. The Python Data Model

In contrast, consider Go. Some objects in that language have features that are magic, in the sense that we cannot emulate them in our own user-defined types. For example, Go arrays, strings, and maps support the use brackets for item access, as in a[i]. But there’s no way to make the [] notation work with a new collection type that you define. Even worse, Go has no user-level concept of an iterable interface or an iterator object, therefore its for/range syntax is limited to supporting five “magic” built-in types, including arrays, strings, and maps.

Maybe in the future, the designers of Go will enhance its metaobject protocol. But currently, it is much more limited than what we have in Python or Ruby.
Go 哈哈哈哈哈哈哈