underscore function

Most of the ovum/underscore family wraps a single method as one node. This one is different: underscore function (search it as "underscore function", the display name) outputs the whole factory - the _ object from underscore3, the bundled Python port of Underscore.js - as a PY_FUNC value. The author's description says it plainly: "Output the underscore factory function _ for Power-Puter."

Power Puter is rgthree's expression node, the one that evaluates a Python-like expression mid-graph - a well-traveled utility in the Comfy ecosystem (rgthree is the pack behind the Power Lora Loader and the "Context" nodes). This node is the bridge between the two: instead of chaining a dozen _. nodes across your graph, you grab the _ factory once and call _.filter(...), _.groupBy(...), _.map(...) inside a Power Puter expression where the whole library is in scope. That's a genuinely neat idea for a messy suite - one wire and the full API is available where expressions are written.

How it works

The node has no inputs at all - required and optional are both empty. Its one output is _ of type PY_FUNC, and the implementation is a one-liner: it returns the underscore factory function itself. That PY_FUNC type is what Power Puter and similar expression nodes accept as an available name inside the evaluated expression. So the flow is: drop this node, wire _ into Power Puter's inputs, and start calling underscore methods in your expression text.

Inputs and output

• Inputs: none.
• Output: _ (PY_FUNC) - the underscore factory function, ready to be named in an expression evaluator.

Installing it

Part of sfinktah/comfy-ovum ("comfy-ovum") - but it only earns its keep if you also have rgthree-comfy installed for Power Puter (both install cleanly side by side; they're the most common utility packs in this corner of the ecosystem):

• ComfyUI Manager: search "comfy-ovum" (and "rgthree" if needed), install, restart.
• Manual: cd ComfyUI/custom_nodes && git clone https://github.com/sfinktah/comfy-ovum, restart.

No model downloads; light dependencies; underscore3 bundled in the repo.

The honest take

This is the one node in the underscore family with a coherent story: it sidesteps the "one node per method, inputs half-wired" problem by handing you the raw API inside an expression. If you already use Power Puter, this is the best reason to install comfy-ovum at all. If you don't use Power Puter, the node does nothing for you - there's no other natural consumer for a bare PY_FUNC. Keep the author's standing WIP caveat in mind, but of all the underscore nodes, this one has the cleanest mechanism and the most predictable payoff.