Analyze Dataset Token Length

analyze-dataset-token-length

OT-Agent trace datasets are conversation-format (ShareGPT-style): each row is {"conversations": [{"role","content"}, …], + metadata} (some use "messages"; metadata fields are e.g. task, result, run_id, trial_name, model, agent). "Token length of a trace" = the tokenized length of the whole conversation.

The canonical OT-Agent tools (don't reinvent)

• scripts/analysis/utils.py::extract_conversation_text(record) — the canonical conversation→full-text extractor (handles messages/conversations, content/value/text, list-of-content-parts). Use this to get the text to tokenize.
• scripts/analysis/context_length_dist.py — token-length distribution across a hardcoded DATASETS list: loads each (load_dataset(..., split="train")), extract_conversation_text per row, batch-tokenizes with the Qwen/Qwen3-8B tokenizer (add_special_tokens=False), prints median / p90 / max, and plots histograms. To analyze a specific dataset, add its HF id to DATASETS and run it (otagent python). This is the go-to for "how long are these traces."
• scripts/analysis/context_length_compare.py — cross-dataset context-length comparison.

Tokenizer convention

Always Qwen/Qwen3-8B (AutoTokenizer.from_pretrained("Qwen/Qwen3-8B", trust_remote_code=True)). Our trace datasets are Qwen3-8B-tokenized even when named for GLM/Kimi/etc. — those "GLM-4.7-…" models are Qwen3-8B SFTs (see memory reference_glm47_swesmith_is_qwen3_8b); the served model name in a row's model field (e.g. hosted_vllm/<numeric-id>) is NOT a usable tokenizer name.

Two token-count methods — pick by the question

• plain = tokenizer(extract_conversation_text(row), add_special_tokens=False) — what context_length_dist.py uses; fast; slightly under-counts vs training (no chat-template tokens). Right for distribution/relative comparisons.
• training-faithful = len(tokenizer.apply_chat_template(conv, tokenize=True, add_generation_prompt=False)) — what an SFT trainer actually tokenizes; use when the question is "does it fit a 32k/131k training window." (Wrap per-row in try/except: if a trace's role shape makes the template raise, fall back to the plain count and tally the fallbacks.)
• ⚠️ The two can differ by MORE than the wrapper tokens — and in the surprising direction. Qwen3's chat template strips historical <think> blocks from earlier assistant turns, so on thinking-mode traces apply_chat_template can count fewer tokens than plain-concat (which keeps all thinking) — i.e. more traces "fit" under the template. So the "right" count for a < N filter depends on whether your SFT template preserves thinking: default Qwen3 (strips) → optimistic count; a thinking-preserving template (qwen3_thinking_acc.jinja2) → conservative count ≈ plain. Report BOTH and pick by the training template; for a safe "fits 32k" answer use the larger (plain / thinking-preserving) count.

Threshold + metadata filter-count (the common ask)

Recipe: load_dataset (non-streaming) → per row compute (a) the token count and (b) a metadata predicate → count the intersection; report each leg separately so it's auditable. Pattern lives in scripts/analysis/_filter_swesmith_complete_32k.py (a worked one-off — copy + adapt the predicate).

⚠️ The metadata-confound trap (read this before any field predicate)

Instruction text leaks into the trace. Fields like task_complete appear verbatim in the user instruction of EVERY trace (…include "task_complete": true in your response…), so a naive '"task_complete": true' in full_text matches all rows (false 100%). Scope the predicate to the agent's actual emission — i.e. an assistant-role message containing the field, not the prompt:

def agent_complete(conv):
    return any(m.get("role") == "assistant" and '"task_complete": true' in (m.get("content") or "")
               for m in conv)

Always sanity-check the predicate VARIES (not all-true / all-false) before trusting a count — print the per-leg breakdown and an early per-1000-row progress line. (Same caution for any tool-name / status substring: confirm you're matching the agent's output, not the system/user scaffolding.)

How to run

Local, otagent python, HF token sourced; full-dataset tokenization of ~10k multi-turn traces is a few minutes → background it:

source "${DC_AGENT_SECRET_ENV:?set DC_AGENT_SECRET_ENV to the secrets file first}"
/Users/benjaminfeuer/miniconda3/envs/otagent/bin/python scripts/analysis/<script>.py   # run_in_background

First run downloads + caches the parquet (~hundreds of MB). A benign 'NoneType' has no attribute 'ArrowInvalid' on streaming-generator teardown can be ignored (use non-streaming load_dataset anyway).

Worked example — swesmith, "task_complete AND < 32768 tok"

DCAgent2/GLM-4.7-swesmith-sandboxes-with_tests-oracle_verified_120s-maxeps-131k (9437 traces): detect completion via the assistant-scoped "task_complete": true (not the instruction prose), count tokens via apply_chat_template (Qwen3-8B), filter complete AND ct < 32768. Reports three legs — #complete, #<32k, and the intersection — so the filter is auditable. (Early progress 1000/9437: complete=924 / fit32k=886 / both=854 confirmed the predicate varies ≈92%, i.e. the confound was correctly excluded.)