Files
ragflow/rag/app/tag.py
Rodger Blom d8cefcf052 feat: add native Dutch language support for BM25 tokenization (#14140)
## Summary
- Add language-aware Snowball stemmer to `RagTokenizer` supporting 16
languages (Dutch, German, French, Spanish, etc.)
- Thread the KB `language` parameter through the full tokenization
pipeline (14 parser modules + task executor)
- Add Dutch to the frontend language lists and cross-language form

## Problem
RAGFlow uses the English Porter stemmer + WordNet lemmatizer for **all**
BM25 tokenization, regardless of the knowledge base language setting.
This produces incorrect stems for non-English text. For example:

| Dutch word | Dutch stemmer | English Porter |
|---|---|---|
| documenten | document | documenten (unchanged!) |
| gebruikers | gebruiker | gebruik (over-stemmed) |
| instellingen | instell | instellingen (unchanged!) |

This degrades BM25 recall for any non-English knowledge base.

## Solution
NLTK already ships Snowball stemmers for 16 languages. This PR:

1. **`rag/nlp/rag_tokenizer.py`**: Overrides `tokenize()` with
`set_language()` and `_normalize_token()` that selects the correct NLTK
Snowball stemmer. Falls back to Porter for unmapped languages (Chinese,
Japanese, Korean, etc. — these use character-based tokenization anyway).
2. **`rag/nlp/__init__.py`** + **14 `rag/app/*.py` parsers** +
**`rag/svr/task_executor.py`**: Threads the `language` parameter through
`tokenize()`, `tokenize_chunks()`, `tokenize_table()`, and all callers.
3. **Frontend**: Adds Dutch (`Nederlands`) to `LanguageList`,
`LanguageMap`, `LanguageAbbreviationMap`, `LanguageTranslationMap`,
cross-language form field, and `en.ts` locale.

## Backward Compatibility
- Default language is `"English"`, preserving existing behavior for all
current users
- Languages without a Snowball stemmer mapping fall back to Porter (no
change)
- No new dependencies — NLTK Snowball is already bundled
2026-07-06 23:39:56 +08:00

148 lines
5.5 KiB
Python

#
# Copyright 2025 The InfiniFlow Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
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# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
import json
import re
import csv
from copy import deepcopy
from deepdoc.parser.utils import get_text
from rag.app.qa import Excel
from rag.nlp import rag_tokenizer
from common import settings
def beAdoc(d, q, a, eng, row_num=-1):
d["content_with_weight"] = q
d["content_ltks"] = rag_tokenizer.tokenize(q)
d["content_sm_ltks"] = rag_tokenizer.fine_grained_tokenize(d["content_ltks"])
d["tag_kwd"] = [t.strip().replace(".", "_") for t in a.split(",") if t.strip()]
if row_num >= 0:
d["top_int"] = [row_num]
return d
def chunk(filename, binary=None, lang="Chinese", callback=None, **kwargs):
"""
Excel and csv(txt) format files are supported.
If the file is in Excel format, there should be 2 column content and tags without header.
And content column is ahead of tags column.
And it's O.K if it has multiple sheets as long as the columns are rightly composed.
If it's in csv format, it should be UTF-8 encoded. Use TAB as delimiter to separate content and tags.
All the deformed lines will be ignored.
Every pair will be treated as a chunk.
"""
eng = lang.lower() == "english"
rag_tokenizer.tokenizer.set_language(lang)
res = []
doc = {"docnm_kwd": filename, "title_tks": rag_tokenizer.tokenize(re.sub(r"\.[a-zA-Z]+$", "", filename))}
if re.search(r"\.xlsx?$", filename, re.IGNORECASE):
callback(0.1, "Start to parse.")
excel_parser = Excel()
for ii, (q, a) in enumerate(excel_parser(filename, binary, callback)):
res.append(beAdoc(deepcopy(doc), q, a, eng, ii))
return res
elif re.search(r"\.(txt)$", filename, re.IGNORECASE):
callback(0.1, "Start to parse.")
txt = get_text(filename, binary)
lines = txt.split("\n")
comma, tab = 0, 0
for line in lines:
if len(line.split(",")) == 2:
comma += 1
if len(line.split("\t")) == 2:
tab += 1
delimiter = "\t" if tab >= comma else ","
fails = []
content = ""
i = 0
while i < len(lines):
arr = lines[i].split(delimiter)
if len(arr) != 2:
content += "\n" + lines[i]
elif len(arr) == 2:
content += "\n" + arr[0]
res.append(beAdoc(deepcopy(doc), content, arr[1], eng, i))
content = ""
i += 1
if len(res) % 999 == 0:
callback(len(res) * 0.6 / len(lines), ("Extract TAG: {}".format(len(res)) + (f"{len(fails)} failure, line: %s..." % (",".join(fails[:3])) if fails else "")))
callback(0.6, ("Extract TAG: {}".format(len(res)) + (f"{len(fails)} failure, line: %s..." % (",".join(fails[:3])) if fails else "")))
return res
elif re.search(r"\.(csv)$", filename, re.IGNORECASE):
callback(0.1, "Start to parse.")
txt = get_text(filename, binary)
lines = txt.split("\n")
fails = []
content = ""
res = []
reader = csv.reader(lines)
for i, row in enumerate(reader):
row = [r.strip() for r in row if r.strip()]
if len(row) != 2:
content += "\n" + lines[i]
elif len(row) == 2:
content += "\n" + row[0]
res.append(beAdoc(deepcopy(doc), content, row[1], eng, i))
content = ""
if len(res) % 999 == 0:
callback(len(res) * 0.6 / len(lines), ("Extract Tags: {}".format(len(res)) + (f"{len(fails)} failure, line: %s..." % (",".join(fails[:3])) if fails else "")))
callback(0.6, ("Extract TAG : {}".format(len(res)) + (f"{len(fails)} failure, line: %s..." % (",".join(fails[:3])) if fails else "")))
return res
raise NotImplementedError("Excel, csv(txt) format files are supported.")
def label_question(question, kbs):
from api.db.services.knowledgebase_service import KnowledgebaseService
from rag.graphrag.utils import get_tags_from_cache, set_tags_to_cache
tags = None
tag_kb_ids = []
for kb in kbs:
if kb.parser_config.get("tag_kb_ids"):
tag_kb_ids.extend(kb.parser_config["tag_kb_ids"])
if tag_kb_ids:
all_tags = get_tags_from_cache(tag_kb_ids)
if not all_tags:
all_tags = settings.retriever.all_tags_in_portion(kb.tenant_id, tag_kb_ids)
set_tags_to_cache(tags=all_tags, kb_ids=tag_kb_ids)
else:
all_tags = json.loads(all_tags)
tag_kbs = KnowledgebaseService.get_by_ids(tag_kb_ids)
if not tag_kbs:
return tags
tags = settings.retriever.tag_query(question, list(set([kb.tenant_id for kb in tag_kbs])), tag_kb_ids, all_tags, kb.parser_config.get("topn_tags", 3))
return tags
if __name__ == "__main__":
import sys
def dummy(prog=None, msg=""):
pass
chunk(sys.argv[1], from_page=0, to_page=10, callback=dummy)