Jinja fails to parse array subscript operator applied to complex expressions

[pqnet]

Minimal example:

import { tokenize, parse } from '@huggingface/jinja";
template = `{{ fullName.split(' ')[0] }}`
/// Parser Error: Expected closing expression token. OpenSquareBracket !== CloseExpression.
parse(tokenize(template))

Using a temporary variable works, e.g.:
{% set tmp = fullName.split(' ') %}{{ tmp[0] }}

[pqnet]

Example of files that uses this syntax:

https://huggingface.co/deepseek-ai/DeepSeek-R1/blob/main/tokenizer_config.json

[xenova]

Thanks for the report! Although this is python-specific syntax (i.e., not actually in the jinja specification), our goal is to support all chat templates on the HF Hub, so we'll definitely add this!