Go: fix development guide (#16678)

### Summary Go development guide --------- Signed-off-by: Jin Hai <haijin.chn@gmail.com>
2026-07-14 08:58:27 +08:00 · 2026-07-07 15:09:39 +08:00
parent f082675e6f
commit 9eba45249c
3 changed files with 252 additions and 64 deletions
--- a/build.sh
+++ b/build.sh
@@ -118,7 +118,7 @@ check_cpp_deps() {
    print_section "Checking c++ dependencies"

    command -v cmake >/dev/null 2>&1 || { echo -e "${RED}Error: cmake is required but not installed.${NC}"; exit 1; }
-    command -v g++ >/dev/null 2>&1 || { echo -e "${RED}Error: g++ is required but not installed.${NC}"; exit 1; }
+    command -v clang++ >/dev/null 2>&1 || { echo -e "${RED}Error: clang++ is required but not installed.${NC}"; exit 1; }

    if check_pcre2; then
        echo "✓ pcre2 library found"
--- a/internal/development.md
+++ b/internal/development.md
@@ -1,40 +1,45 @@
-# RAGFlow Go Version - Startup Guide
+# RAGFlow Go implementation - Development Guide

-## 1. Start Dependencies
+## 1. Prepare dependencies

-```bash
-docker compose -f docker/docker-compose-base.yml --profile ragflow-go --profile infinity up -d
+### 1.1 Install CMake and build RAGFlow on Ubuntu 24.04
+
+```shell
+sudo apt update
+sudo apt install ca-certificates gpg wget
+test -f /usr/share/doc/kitware-archive-keyring/copyright || wget -O - https://apt.kitware.com/keys/kitware-archive-latest.asc 2>/dev/null | gpg --dearmor - | sudo tee /usr/share/keyrings/kitware-archive-keyring.gpg >/dev/null
+echo 'deb [signed-by=/usr/share/keyrings/kitware-archive-keyring.gpg] https://apt.kitware.com/ubuntu/ noble main' | sudo tee /etc/apt/sources.list.d/kitware.list >/dev/null
+sudo apt update
+test -f /usr/share/doc/kitware-archive-keyring/copyright || sudo rm /usr/share/keyrings/kitware-archive-keyring.gpg
+sudo apt install -y kitware-archive-keyring
+sudo apt update
+sudo apt install -y cmake 
 ```

-## 2. Build Go Version RAGFlow
- Build RAGFlow binary with C++ dependencies:
+### 1.2 Install clang-20

-```bash
-./build.sh
+```shell
+sudo apt install clang-20 lld-20
+sudo ln -s /usr/bin/clang++-20 /usr/bin/clang++
+sudo ln -s /usr/bin/clang-20 /usr/bin/clang
+sudo ln -s /usr/bin/ld.lld-20 /usr/bin/ld.lld
 ```

- Production builds (strip debug symbols for smaller binaries):
+### 1.3 Install golang

-```bash
-./build.sh --strip --all
-# or
-./build.sh -s --go
+```shell
+wget https://go.dev/dl/go1.25.4.linux-amd64.tar.gz
+sudo rm -rf /usr/local/go
+sudo tar -C /usr/local -xzf go1.23.4.linux-amd64.tar.gz
+echo 'export PATH=$PATH:/usr/local/go/bin' >> ~/.bashrc
+source ~/.bashrc
+go version
 ```

-### 2.1. Native Static Libraries
-
-Before building, you need three native static libraries (pdfium, pdf_oxide, office_oxide).
-They are **not** downloaded by `build.sh` — use the included download script:
-
-```bash
-# From the project root, download and extract to ~/ragflow-native-libs/
-uv run python3 ragflow_deps/download_deps.py
-```
-
-This also requires `lld-20` on Linux (for Chromium-built pdfium):
-
-```bash
-sudo apt install lld-20 && sudo ln -s /usr/bin/ld.lld-20 /usr/bin/ld.lld
+### 1.4 Install dependent library
+```shell
+sudo apt install libpcre2-dev
+python3 ragflow_deps/download_go_deps.py
 ```

 > **Note**: If you use IDEs like GoLand to run/debug directly (via Run/Debug buttons), or run `go build` / `go run` from command line, set these CGO environment variables:
@@ -56,7 +61,31 @@ sudo apt install lld-20 && sudo ln -s /usr/bin/ld.lld-20 /usr/bin/ld.lld
 >
 > All three native libraries are statically linked — no `LD_LIBRARY_PATH` or `-Wl,-rpath` needed.

-## 3. Run Go Version RAGFlow
+
+### 1.5 Build RAGFlow
+
+- Build binary
+```bash
+./build.sh
+```
+
+- Production builds (strip debug symbols for smaller binaries):
+
+```bash
+./build.sh --strip --all
+# or
+./build.sh -s --go
+```
+
+## 2. Start RAGFlow
+
+- Start dependencies
+```bash
+docker compose -f docker/docker-compose-base.yml --profile ragflow-go --profile infinity up -d
+```
+
+
+- Start RAGFlow
 Note: admin server must be started first; otherwise, api server will encounter errors when sending heartbeats.

 ```bash
@@ -84,18 +113,18 @@ Note: admin server must be started first; otherwise, api server will encounter e
 ./bin/ragflow-cli --admin
 ```

-## 4. Start Frontend
+## 3. Start Frontend
 ```bash
 cd web && export API_PROXY_SCHEME=hybrid && npm run dev
 ```

-## 5. Service Ports & API Routing
+## 4. Service Ports & API Routing
 - api server listens on port 9384 by default
 - admin server listens on port 9383 by default

 After updating or implementing an API, update the frontend development environment routes in web/vite.config.ts under proxySchemes.

-### Proxy Schemes
+### 4.1 Proxy Schemes

 | Scheme | Description |
 |--------|-------------|
@@ -104,11 +133,11 @@ After updating or implementing an API, update the frontend development environme
 | `go` | All API requests from the frontend are routed to the Go server |


-## 6. RAGFlow commands
+## 5. RAGFlow commands

 You can use the following CLI commands to test the corresponding API implementations.

-### 6.1. Run ragflow-cli, register user, login, and logout:
+### 5.1. Run ragflow-cli, register user, login, and logout:

 ```
 $ ./ragflow-cli
@@ -124,19 +153,19 @@ RAGFlow(api/default)> logout;
 SUCCESS
 ```

-### 6.2. List currently supported providers
+### 5.2. List currently supported providers
 ```
 RAGFlow(api/default)> list available providers;
 ```

-### 6.3. Add or delete a provider for the current tenant
+### 5.3. Add or delete a provider for the current tenant
 ```
 RAGFlow(api/default)> add provider 'openai';
 ```
 ```
 RAGFlow(api/default)> delete provider 'openai';
 ```
-### 6.4. Create a model instance for a specific provider
+### 5.4. Create a model instance for a specific provider
 ```
 RAGFlow(api/default)> create provider 'openai' instance 'instance_name' key 'api-key';
 ```
@@ -148,18 +177,18 @@ For locally deployed models (e.g., ollama, vLLM), use the following command to a
 ```
 RAGFlow(api/default)> create provider 'vllm' instance 'instance_name' key '' url 'http://192.168.1.96:8123/v1';
 ```
-### 6.5. List and delete an instance
+### 5.5. List and delete an instance
 ```
 RAGFlow(api/default)> list instances from 'openai';
 ```
 ```
 RAGFlow(api/default)> drop instance 'instance_name' from 'openai';
 ```
-### 6.6. List models supported by a model instance
+### 5.5. List models supported by a model instance
 ```
 RAGFlow(api/default)> list models from 'openai' 'instance_name';
 ```
-### 6.7. Chat with LLM
+### 5.7. Chat with LLM
 - Chat
 ```
 RAGFlow(api/default)> chat with 'glm-4.5-flash@test@zhipu-ai' message '20 words introduce LLM';
@@ -196,11 +225,11 @@ Time: 31.600545
 ```
 RAGFlow(api/default)> chat with 'glm-4.6v-flash@test@zhipu-ai' message 'What are the video talk about?' video 'https://cdn.bigmodel.cn/agent-demos/lark/113123.mov'
 Answer: Based on the sequence of frames provided, the video is a demonstration of a web search and navigation process...
-Time: 76.582520
+Time: 75.582520
 ```
 Note: Both image and video understanding support streaming and thinking modes as well.

-### 6.8. Chat completions
+### 5.8. Chat completions

 ```
 RAGFlow(api/default)> chat completion 'hello'
@@ -225,7 +254,7 @@ RAGFlow(api/default)> CHAT COMPLETIONS 'Continue' \
                      history_delimiter ';';
 ```

-### 6.9. Chat with OpenAI compatible API
+### 5.9. Chat with OpenAI compatible API

 ```
 RAGFlow(api/default)> openai_chat '<chat_id>' 'Hello, how are you?';
@@ -263,17 +292,17 @@ RAGFlow(api/default)> openai_chat '<chat_id>' 'Hello, how are you?' extra_body '
 CLI error: OPENAI_CHAT extra_body: unknown field "ref" (valid: reference, reference_metadata, metadata_condition)
 ```

-### 6.10. Generate Embeddings
+### 5.10. Generate Embeddings
 ```
 RAGFlow(api/default)> embed text 'what is rag' 'who are you' with 'embedding-3@test@zhipu-ai' dimension 16;
 ```

-### 6.11. Document Reranking
+### 5.11. Document Reranking
 ```
 RAGFlow(api/default)> rerank query 'what is rag' document 'rag is retrieval augment generation' 'rag need llm' 'famous rag project includes ragflow' with 'rerank@test@zhipu-ai' top 2;
 ```

-### 6.12. Get supported models from provider API
+### 5.12. Get supported models from provider API

 ```
 RAGFlow(api/default)> list supported models from 'gitee' 'test';
@@ -295,7 +324,7 @@ RAGFlow(api/default)> list supported models from 'gitee' 'test';
 +-----------+---------------------------+---------------+------------+-----------------------------------------------------------------+----------------------------------------------------------+---------------------------------------------+
 ```

-### 6.13. Get preset models of a provider
+### 5.13. Get preset models of a provider

 ```
 RAGFlow(api/default)> list models from 'minimax';
@@ -313,7 +342,7 @@ RAGFlow(api/default)> list models from 'minimax';
 +------------+-------------+------------------------+
 ```

-### 6.14. List instances of a provider
+### 5.14. List instances of a provider

 ```
 RAGFlow(api/default)> list instances from 'zhipu-ai';
@@ -324,7 +353,7 @@ RAGFlow(api/default)> list instances from 'zhipu-ai';
 +---------+----------------------+----------------------------------+--------------+----------------------------------+--------+
 ```

-### 6.15. Show instance of a provider
+### 5.15. Show instance of a provider
 ```
 RAGFlow(api/default)> show instance 'test' from 'zhipu-ai';
 +----------------------------------+--------------+----------------------------------+---------+--------+
@@ -334,7 +363,7 @@ RAGFlow(api/default)> show instance 'test' from 'zhipu-ai';
 +----------------------------------+--------------+----------------------------------+---------+--------+
 ```

-### 6.16. List models of a specific instance
+### 5.15. List models of a specific instance

 ```
 RAGFlow(api/default)> list models from 'minimax' 'test';
@@ -352,7 +381,7 @@ RAGFlow(api/default)> list models from 'minimax' 'test';
 +------------+-------------+------------------------+--------+
 ```

-### 6.17. List added providers
+### 5.17. List added providers
 ```
 RAGFlow(api/default)> list providers;
 +--------------------------------------------------------------------------+-------------+--------------+
@@ -364,7 +393,7 @@ RAGFlow(api/default)> list providers;
 +--------------------------------------------------------------------------+-------------+--------------+
 ```

-### 6.18. Deactivate / activate a model
+### 5.18. Deactivate / activate a model

 ```
 RAGFlow(api/default)> disable model 'deepseek-v4-pro' from 'deepseek' 'test';
@@ -380,7 +409,7 @@ RAGFlow(api/default)> enable model 'deepseek-v4-pro' from 'deepseek' 'test';
 SUCCESS
 ```

-### 6.19. Set current model
+### 5.19. Set current model
 ```
 RAGFlow(api/default)> use model 'glm-4.5-flash@test@zhipu-ai';
 SUCCESS
@@ -389,7 +418,7 @@ Answer: Large language models are advanced AI systems. They process text to unde
 Time: 1.680416
 ```

-### 6.20. Set, reset, and list default models
+### 5.20. Set, reset, and list default models
 ```
 RAGFlow(api/default)> set default chat model 'glm-4.5-flash@test@zhipu-ai';
 SUCCESS
@@ -433,7 +462,7 @@ RAGFlow(api/default)> list default models;
 +--------+----------------+--------------+----------------+------------+
 ```

-### 6.21. Show current balance of a provider instance
+### 5.21. Show current balance of a provider instance
 ```
 RAGFlow(api/default)> show balance from 'gitee' 'test';
 +-------------+----------+
@@ -443,13 +472,13 @@ RAGFlow(api/default)> show balance from 'gitee' 'test';
 +-------------+----------+
 ```

-### 6.22. Check provider instance availability
+### 5.22. Check provider instance availability
 ```
 RAGFlow(api/default)> check instance 'test' from 'zhipu-ai';
 SUCCESS
 ```

-### 6.23. Add local model to RAGFlow, only for local deployed inference server, such as ollama
+### 5.23. Add local model to RAGFlow, only for local deployed inference server, such as ollama
 ```
 RAGFlow(api/default)> add model 'Qwen/Qwen2.5-0.5B' to provider 'vllm' instance 'test' with tokens 131072 chat;
 SUCCESS
@@ -463,7 +492,7 @@ RAGFlow(api/default)> drop model 'Qwen/Qwen2.5-0.5B' from 'vllm' 'test';
 SUCCESS
 ```

-### 6.24. List datasets
+### 5.24. List datasets
 ```
 RAGFlow(api/default)> list datasets;
 +-------------+--------------+----------------+----------------------+----------------------------------+----------+------+----------+------------+----------------------------------+-----------+---------------+
@@ -474,14 +503,14 @@ RAGFlow(api/default)> list datasets;
 +-------------+--------------+----------------+----------------------+----------------------------------+----------+------+----------+------------+----------------------------------+-----------+---------------+
 ```

-### 6.25. Text to Speech
+### 5.25. Text to Speech
 ```
 RAGFlow(api/default)> tts with 'speech-2.8-hd@test@minimax' text 'He who desires but acts not, breeds pestilence.' play format 'wav' save './internal' param '{"voice_setting": {"voice_id": "English_radiant_girl", "speed": 1, "vol": 1, "pitch": 0}, "audio_setting": {"sample_rate": 32000, "bitrate": 128000, "format": "wav", "channel": 1}, "output_format": "hex"}'
 Saved to directory: /home/infiniflow/Documents/development/ragflow/internal/speech-2.8-hd_output.wav
 SUCCESS
 ```

-### 6.26. Audio to Speech
+### 5.25. Audio to Speech
 ```
 RAGFlow(api/default)> asr with 'FunAudioLLM/SenseVoiceSmall@test@siliconflow' audio './internal/test.wav' param ''
 +----------------------------------------------------------------------------------------------------------------------+
@@ -491,7 +520,7 @@ RAGFlow(api/default)> asr with 'FunAudioLLM/SenseVoiceSmall@test@siliconflow' au
 +----------------------------------------------------------------------------------------------------------------------+
 ```

-### 6.27. Optical Character Recognition
+### 5.27. Optical Character Recognition
 ```
 RAGFlow(api/default)> ocr with 'paddleocr-vl-0.9b@test@baidu' file './internal/text.jpg'
 +------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
@@ -501,7 +530,7 @@ RAGFlow(api/default)> ocr with 'paddleocr-vl-0.9b@test@baidu' file './internal/t
 +------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
 ```

-### 6.28. Chunk Management Commands
+### 5.28. Chunk Management Commands

 - Create a chunk store with vector size
 ```
@@ -548,7 +577,7 @@ RAGFlow(api/default)> RETRIEVE 'AI' ON DATASETS 'test'
 RAGFlow(api/default)> GET CHUNK '29cc4f6d7a5c6e7c' OF DATASET 'test' DOCUMENT 'bbe55942535e11f1bc5184ba59049aa3' IN DATASET 'test'
 ```

-### 6.29. Metadata Management Commands
+### 5.29. Metadata Management Commands

 - Create metadata store
 ```
@@ -584,7 +613,7 @@ RAGFlow(api/default)> DROP METADATA STORE
 RAGFlow(api/default)> GET METADATA OF DATASET 'test' 'test2'
 ```

-### 6.30. Search datasets
+### 5.30. Search datasets

 - Search datasets using SQL-like dataset search syntax:
 ```
--- a/ragflow_deps/download_go_deps.py
+++ b/ragflow_deps/download_go_deps.py
@@ -0,0 +1,159 @@
+#!/usr/bin/env python3
+
+# PEP 723 metadata
+# /// script
+# requires-python = ">=3.10"
+# dependencies = [
+#   "nltk",
+#   "huggingface-hub"
+# ]
+# ///
+
+# This script downloads every artifact that the `infiniflow/ragflow_deps`
+# Docker image bakes in. Run it from anywhere — the `__main__` block
+# chdir's into this file's own directory, so all outputs land under
+# `ragflow_deps/` regardless of the caller's CWD.
+#
+# Build-context relationship: `ragflow_deps/Dockerfile` is built with
+# `ragflow_deps/` as its build context, so the files written here MUST
+# sit at the top of `ragflow_deps/`. The Dockerfile's COPY lines assume
+# top-level paths (`huggingface.co`, `nltk_data`, `cl100k_base.tiktoken`,
+# `*.deb`, `*.jar`, `*.tar.gz`, `stagehand-server-v3-linux-<arch>`).
+#
+# Typical workflow:
+#
+#   uv run python3 ragflow_deps/download_deps.py            # download
+#   cd ragflow_deps
+#   docker build -f Dockerfile -t infiniflow/ragflow_deps .
+#
+# The main `Dockerfile` (built from the project root) pulls this image
+# via `--mount=type=bind,from=infiniflow/ragflow_deps:latest,...` and
+# is unaffected by where these files live locally.
+
+import argparse
+import os
+import sys
+import requests
+from typing import Union
+
+def get_urls(use_china_mirrors=False) -> list[Union[str, list[str]]]:
+    if use_china_mirrors:
+        return [
+            # stagehand-server-v3 Node.js SEA binaries (used by Browser
+            # component in local mode).
+            #
+            # The stagehand-go Go module (pinned in go.mod) and the
+            # stagehand-server binary (this release) are LOOSELY
+            # MATCHED — both stay on the v3.x line and remain
+            # protocol-compatible. The two version numbers do NOT
+            # track each other: the Go SDK is at v3.21.0 while the
+            # current latest server release is v3.7.2.
+            #
+            # On every go.mod bump, refresh this URL to the current
+            # latest server release. There is no version
+            # correspondence to maintain; "both on v3.x" is the
+            # compatibility contract.
+            "https://gh-proxy.com/https://github.com/browserbase/stagehand/releases/download/stagehand-server-v3/v3.7.2/stagehand-server-v3-linux-x64",
+            "https://gh-proxy.com/https://github.com/browserbase/stagehand/releases/download/stagehand-server-v3/v3.7.2/stagehand-server-v3-linux-arm64",
+            # Native static libraries for Go build (pdfium, pdf_oxide, office_oxide)
+            # Used by build.sh's check_*_deps functions — pre-downloaded to avoid
+            # network access during CI.
+            ["https://gh-proxy.com/https://github.com/kognitos/pdfium-static/releases/download/chromium%2F7809/pdfium-linux-x64-static.tgz", "pdfium-linux-x64-static.tgz"],
+            ["https://gh-proxy.com/https://github.com/yfedoseev/pdf_oxide/releases/download/v0.3.73/pdf_oxide-go-ffi-linux-amd64.tar.gz", "pdf_oxide-go-ffi-linux-amd64.tar.gz"],
+            ["https://gh-proxy.com/https://github.com/yfedoseev/office_oxide/releases/download/v0.1.3/native-linux-x86_64.tar.gz", "office_oxide-linux-x86_64.tar.gz"],
+        ]
+    else:
+        return [
+            # stagehand-server-v3 Node.js SEA binaries (used by Browser
+            # component in local mode).
+            #
+            # The stagehand-go Go module (pinned in go.mod) and the
+            # stagehand-server binary (this release) are LOOSELY
+            # MATCHED — both stay on the v3.x line and remain
+            # protocol-compatible. The two version numbers do NOT
+            # track each other: the Go SDK is at v3.21.0 while the
+            # current latest server release is v3.7.2.
+            #
+            # On every go.mod bump, refresh this URL to the current
+            # latest server release. There is no version
+            # correspondence to maintain; "both on v3.x" is the
+            # compatibility contract.
+            "https://github.com/browserbase/stagehand/releases/download/stagehand-server-v3/v3.7.2/stagehand-server-v3-linux-x64",
+            "https://github.com/browserbase/stagehand/releases/download/stagehand-server-v3/v3.7.2/stagehand-server-v3-linux-arm64",
+            # Native static libraries for Go build (pdfium, pdf_oxide, office_oxide)
+            # Used by build.sh's check_*_deps functions — pre-downloaded to avoid
+            # network access during CI.
+            ["https://github.com/kognitos/pdfium-static/releases/download/chromium%2F7809/pdfium-linux-x64-static.tgz", "pdfium-linux-x64-static.tgz"],
+            ["https://github.com/yfedoseev/pdf_oxide/releases/download/v0.3.73/pdf_oxide-go-ffi-linux-amd64.tar.gz", "pdf_oxide-go-ffi-linux-amd64.tar.gz"],
+            ["https://github.com/yfedoseev/office_oxide/releases/download/v0.1.3/native-linux-x86_64.tar.gz", "office_oxide-linux-x86_64.tar.gz"],
+        ]
+
+
+def download_with_progress(url, filename):
+    response = requests.get(url, stream=True)
+    total_size = int(response.headers.get('content-length', 0))
+    block_size = 1024
+
+    with open(filename, 'wb') as file:
+        downloaded = 0
+        for data in response.iter_content(block_size):
+            file.write(data)
+            downloaded += len(data)
+
+            if total_size > 0:
+                progress = (downloaded / total_size) * 100
+                sys.stdout.write(f'\rProgress: {progress:.1f}% ({downloaded}/{total_size} bytes)')
+                sys.stdout.flush()
+
+    print()
+
+
+if __name__ == "__main__":
+    # Anchor CWD to this file's directory so all relative outputs
+    # (huggingface.co/, nltk_data/, *.deb, *.jar, *.tar.gz, etc.) land
+    # at the top of ragflow_deps/ regardless of where the user invokes
+    # the script from. This is the build context for `ragflow_deps/Dockerfile`.
+    os.chdir(os.path.dirname(os.path.abspath(__file__)))
+
+    parser = argparse.ArgumentParser(description="Download dependencies with optional China mirror support")
+    parser.add_argument("--china-mirrors", action="store_true", help="Use China-accessible mirrors for downloads")
+    args = parser.parse_args()
+
+    urls = get_urls(args.china_mirrors)
+
+    # Some mirrors (e.g. archive.ubuntu.com) reject the default urllib
+    # User-Agent with HTTP 403, so install an opener with a browser-like UA.
+#     opener = urllib.request.build_opener()
+#     opener.addheaders = [("User-Agent", "Mozilla/5.0")]
+#     urllib.request.install_opener(opener)
+
+    for url in urls:
+        download_url = url[0] if isinstance(url, list) else url
+        filename = url[1] if isinstance(url, list) else url.split("/")[-1]
+        print(f"Downloading {filename} from {download_url}...")
+        if not os.path.exists(filename):
+            download_with_progress(download_url, filename)
+
+    # Extract native static libraries to ~/ragflow-native-libs for Go build.
+    # Ensures build.sh can find them without network access.
+    native_deps_dir = os.path.expanduser("~/ragflow-native-libs")
+    extractions = [
+        ("pdfium-linux-x64-static.tgz", "pdfium-static"),
+        ("pdf_oxide-go-ffi-linux-amd64.tar.gz", "pdf_oxide"),
+        ("office_oxide-linux-x86_64.tar.gz", "office_oxide"),
+    ]
+    import tarfile
+
+    for archive, subdir in extractions:
+        archive_path = os.path.join(os.getcwd(), archive)
+        if not os.path.isfile(archive_path):
+            print(f"  Skipping extraction: {archive} not found")
+            continue
+        target = os.path.join(native_deps_dir, subdir)
+        if os.path.isdir(target):
+            print(f"  ✓ {subdir} already extracted to {target}")
+            continue
+        os.makedirs(target, exist_ok=True)
+        print(f"  Extracting {archive} → {target}")
+        with tarfile.open(archive_path) as tf:
+            tf.extractall(target)