Py String To List

Lists are everywhere in data work - a set of categories, a list of column names, a sequence of numbers - and in a node graph they usually start life as text. Py String To List is the parser: type a Python list literal into a multiline box, get a real PYLIST out.

It's the mirror of Py List To String, and together they're a clean round trip: convert a list to text for display or storage, then parse it back when you need the actual list again.

How it works

The node uses ast.literal_eval() on your text, so the input must be a valid Python list literal. [1, 2, 3] and ["apple", "banana"] work; list(range(5)) does not, because that's an expression, not a literal. literal_eval is safe - it won't execute arbitrary code - but it's strict about syntax.

One JSON gotcha carries over from the pack's other literal-parsing nodes: Python booleans, not JSON's. So [true, false] fails; [True, False] works. If you're feeding it JSON-style arrays, mind the case on booleans and null.

Inputs and outputs

• data - the multiline string holding your list literal.

Output: a PYLIST - the parsed list, ready for list-consuming nodes or Py List To String for the trip back to text.

Install

Ships in HowToSD/ComfyUI-Data-Analysis. Manager: search "Data analysis" in the Custom Node Manager, install ComfyUI-Data-Analysis, restart, reload the browser. Manual:

cd ComfyUI/custom_nodes
git clone https://github.com/HowToSD/ComfyUI-Data-Analysis.git
mv ComfyUI-Data-Analysis data-analysis   # README: example workflows expect this folder name
pip install -r requirements.txt

No models, no GPU - parsing is all it does.

Common issues

Syntax errors are the whole risk surface, and they're loud. Missing brackets, a stray true instead of True, or a trailing comma where Python doesn't want one will all raise. Empty list is fine as []. And remember, single values like "42" parse as a string, not a list - if you need a one-element list, type [42]. When in doubt, run Py List To String on an existing list to see exactly what literal text the parser will accept, then copy that.