_.isBuiltinMethod

_.isBuiltinMethod tells you whether a value is a Python built-in method - a method implemented in C that belongs to a built-in type, like "hello".upper, [1,2].append, or {}.keys. It's the sibling of _.isBuiltinFunction (for bare built-ins like len) and part of the same family of Python-type checks this pack ports.

How it works

Another exact-type test:

def isBuiltinMethod(self):
    return self._wrap(type(self.obj) is BuiltinMethodType)

The fine line that matters here: a method you defined on your own class is MethodType. A built-in method attached to a built-in object is BuiltinMethodType. The check distinguishes the two precisely, so [1,2,3].append passes and a custom class's method fails.

The inputs that matter

One input, one output:

• obj - the primary input (*), the value being inspected. Also accepts a _.CHAIN to continue chaining.

Output is a single * - a real bool at runtime, untyped on the socket, since the auto-generator only types the standard Underscore.js method names.

Where you'd actually use it

Same honest answer as its sibling: this is introspection for meta-work, not a daily driver. To even hold a built-in method as a graph value, you'd be operating at the level where _.invoke is calling methods you fetched at runtime, or you're building iteratees from function-typed sockets. If you're in that rare territory, _.isBuiltinMethod lets you confirm what a value is before calling it - a poor-man's type guard. In an ordinary image or video workflow, it'll sit unused, and that's fine.

Installing

Part of comfy-ovum (MIT). ComfyUI Manager → search comfy-ovum → install → restart, or:

cd ComfyUI/custom_nodes
git clone https://github.com/sfinktah/comfy-ovum

No extra dependencies for the underscore nodes themselves - the bundled underscore3 port covers them.

Gotchas

Unset typed output (*), WIP status per the pack README, and a narrow definition: it checks BuiltinMethodType exactly, so it won't match plain functions, lambdas, or user-defined methods. If you want the broad "can I call this?" test, _.isCallable is the one; if you want "is it a built-in method specifically," this is it.