lstrip

Text that comes from a file, an API, or a shared workflow tends to accumulate leading junk: spaces, tabs, newlines, the occasional stray character. lstrip removes whatever's hanging off the front of a string. By default that's all leading whitespace; give it a chars argument and it strips any of those characters instead.

You'd reach for it when cleaning loaded text before it's processed - trimming the leading whitespace off a line you read from a file, stripping an unwanted # off a comment line, or normalizing input so a comparison or parse downstream gets clean text. It's the front-end twin of rstrip, and both are usually applied in the same cleanup chain.

How it works

Python's str.lstrip(chars), with one deliberate behavior built into the node: if you leave chars empty (the default), it becomes None, which means "strip all leading whitespace" - spaces, tabs, newlines, the works. If you do provide chars, it's treated as a set of characters, not a prefix. lstrip("ab") strips any leading a or b, in any mix - it won't just remove the literal substring "ab".

Examples: " hi" → "hi". "\n\tprompt" → "prompt". "###note".lstrip("#") → "note".

Inputs and outputs

• string - required, the text to clean.
• chars - optional STRING, default "". Leave empty for whitespace-stripping mode; fill it with the specific characters to remove.

Output is one STRING - the cleaned copy.

Installing it

Part of the Basic data handling pack by StableLlama. ComfyUI Manager, search "Basic data handling", install, restart. Or:

cd ComfyUI/custom_nodes
git clone https://github.com/StableLlama/ComfyUI-basic_data_handling

Pure Python, no dependencies, no downloads - installs clean, which is the pack's calling card. Under Basic/STRING in the menu.

Common issues

The set-vs-prefix confusion is the big one. People type chars="ab" expecting to remove the exact word "ab" from the front, and instead get every leading a and b stripped. If you want an exact prefix removed, use the pack's removeprefix node instead - that's the literal one. Also note that in whitespace mode lstrip removes all leading whitespace including newlines, so if you only wanted to remove a single trailing newline, this will happily eat an entire indentation block too. That's usually what you want when cleaning text, just don't be surprised by the enthusiasm.