tools/wer.py

# tools/wer.py
from __future__ import annotations

from typing import List, Tuple
import string

from jiwer import process_words
from zhon.hanzi import punctuation as zh_punctuation

# 中文标点 + 英文标点 + '-'
_PUNCTUATION_ALL = zh_punctuation + string.punctuation + "-"


def _normalize_pair(gt: str, gen: str, lang: str) -> Tuple[str, str]:
    gt = "" if gt is None else str(gt)
    gen = "" if gen is None else str(gen)

    # 去标点（保留 "'"）
    for x in _PUNCTUATION_ALL:
        if x == "'":
            continue
        gt = gt.replace(x, "")
        gen = gen.replace(x, "")

    # 统一空格与连字符
    gt = gt.replace("  ", " ").replace("-", " ")
    gen = gen.replace("  ", " ").replace("-", " ")

    if lang == "zh":
        # 把“字”当作 token
        gt = " ".join([ch for ch in gt])
        gen = " ".join([ch for ch in gen])
    elif lang == "en":
        gt = gt.lower()
        gen = gen.lower()
    else:
        raise NotImplementedError("lang must be 'zh' or 'en'")

    return gt, gen


def compute_wers(gt_texts: List[str], gen_texts: List[str], lang: str = "zh") -> List[float]:
    if len(gt_texts) != len(gen_texts):
        raise ValueError(f"Length mismatch: {len(gt_texts)} != {len(gen_texts)}")

    wers: List[float] = []
    for gt_raw, gen_raw in zip(gt_texts, gen_texts):
        gt_norm, gen_norm = _normalize_pair(gt_raw, gen_raw, lang=lang)
        measures = process_words(reference=gt_norm, hypothesis=gen_norm)
        wers.append(float(measures.wer))
    return wers



if __name__ == "__main__":
    gt = ["你好世界啊", "今天天气不对", "abc-def"]
    gen = ["你好，世界！", "今天 天气 不错", "abc def"]
    print(compute_wers(gt, gen, lang="zh"))
    print(compute_wers(["Hello World"], ["hello, world!"], lang="en"))