String Left

String Left grabs the first N characters of a string - Excel's LEFT, minus the spreadsheet. Give it text and a num_chars, get the leftmost slice back. It's the smallest, plainest node in the TakkunRed ComfyUI-String-Function pack, and together with String Mid and String Right it gives you the three slicing primitives you need to parse text that arrives in a fixed layout.

Where does that actually come up in an image workflow? Fixed-width text. A filename where the batch number is always the first three characters (042_forest.png - take the left 3). A generated tag list where the category prefix is always up front. LLM outputs that follow a strict "X - description" shape, where X is a fixed length you can slice off. When the text is positional, string math beats regex because there's nothing to miscompile.

How it works

It's one Python slice: text[:num_chars]. Nothing clever, nothing surprising - which is exactly the point of a utility node like this. num_chars=0 returns an empty string, and a num_chars larger than the string length just returns the whole string (Python slices clamp gracefully).

One thing to keep in mind: num_chars counts characters, and with a normal Unicode string that means what you'd expect for ASCII, but for multibyte text it counts Unicode code points. If you're slicing a Japanese or emoji-containing string, num_chars=2 takes two characters as a person sees them in most cases - not two raw bytes.

Inputs and outputs

Two required inputs: text (multiline, so pasting a block is fine) and num_chars (INT, default 1, range 0–99999). One output: result (STRING).

The only real decision is the count. Set it once and it's a pure pass-through transform you can drop into a string chain.

Installing it

Same pack, same zero-dependency story:

cd ComfyUI/custom_nodes
git clone https://github.com/TakkunRed/ComfyUI-String-Function

Or search "ComfyUI-String-Function" in ComfyUI Manager, restart, and it's under String Function.

Where people get burned

• It's the left N characters, not the first N "tokens" or "words." If you want the first word, you want a split on whitespace, not a Left with num_chars=5.
• Positional slicing is brittle - if the layout of your upstream text shifts by one character, every slice silently returns the wrong thing. Reach for String Regex Match when the structure is loose, and for Left/Mid/Right only when it's genuinely fixed.
• There's no trim inside the slice. "ab c" with num_chars=3 gives you "ab " - if trailing spaces are a problem, run a String Trim after.

For a node this thin, that's it: a slice, an integer, done. It earns its place next to its two siblings, and the three of them together cover every "cut at this position" graph you'll build.