Autolang provides fully automatic, maintenance-free multilingual support for Python projects. It analyzes and collects context, then sends it to an LLM for translation.

Autolang 为 Python 项目提供全自动、免维护的多语言支持。它会分析并收集上下文，然后发送给大模型进行翻译。

It does not restrict the source language of your text. If your project has collaborators from different countries or regions, they can write in their native languages.

它不限制文本的源语言。如果你的项目有来自不同国家或地区的协作者，他们可以直接使用自己的母语编写内容。

Its responsibility is intentionally narrow:

它的职责刻意保持得很薄：

• Extract _() strings from source code with Babel and maintain pot/po files, which are GNU-standard localization files.
• Translate untranslated entries in po files through an OpenAI-compatible API, while using code comments and already translated text from the same file as reference context.
• Compile the results into binary mo files at the end.

• 用 Babel 提取源码中的 _() 文本并维护 pot/po 文件，这些文件是 GNU 标准的多语言文件。
• 通过 OpenAI 兼容接口翻译 po 文件中的未翻译条目，并把代码注释、同一文件中已经翻译的文本作为参考上下文。
• 最后将结果编译为二进制 mo 文件。

A typical flow looks like this:

典型流程如下：

1. Wrap user-facing text with gettext in Python code.
2. Run autolang init to initialize the locale directory and po files.
3. Run autolang sync and autolang translate in your CI/CD workflow to keep po files synchronized with source code and let the LLM fill in missing translations.

1. 在 Python 代码里用 gettext 包裹面向用户的文案。
2. 执行 autolang init 初始化语言目录和 po 文件。
3. 在 CI/CD 工作流中执行 autolang sync 和 autolang translate，让 po 文件与源码保持同步，并交给大模型补全缺失翻译。

Example source code:

示例源码：

from gettext

# i18n.py for setting up the translator / i18n.py，用于设置翻译器
def get_system_language() -> str:
    if sys.platform == "win32":
        import ctypes
        lang_id = ctypes.windll.kernel32.GetUserDefaultUILanguage()
        return locale.windows_locale.get(lang_id)
    else:
        return locale.getlocale()

translator = gettext.translation(
            "messages",
            localedir="i18n",
            languages=[get_system_language(), "en"],
            fallback=True,
        )
_ = translator.gettext

# Your application code / 你的应用代码
print(_("Hello {name}").format(name="alice"))
print(_("保存成功"))

Just add it to your development dependencies:

只需将它加入开发依赖：

uv add --dev autolang

CLI entry point:

CLI 入口：

uv run autolang --help

Initialize the directory structure and po files for the target locales. The command first runs pybabel extract to generate a pot file, then runs pybabel init for each locale.

初始化目标语言的目录结构和 po 文件。命令会先调用 pybabel extract 生成 pot 文件，再对每个语言执行 pybabel init。

uv run autolang init -d i18n -l en -l zh --source ./src

Common arguments:

常用参数：

• -d, --directory: Locale directory. Default: i18n
• -l, --locale: Target locale. Can be passed multiple times
• --source: Source code path to scan. Can be passed multiple times

• -d, --directory: 语言目录，默认 i18n
• -l, --locale: 目标语言，可重复传入
• --source: 需要扫描的源码路径，可重复传入

After initialization, the directory usually looks like this:

初始化后目录通常类似：

i18n/
  messages.pot
  en/LC_MESSAGES/messages.po
  zh/LC_MESSAGES/messages.po

Synchronize source strings into the po files for all locales. The command reruns pybabel extract and pybabel update.

将源码文案同步到所有语言的 po 文件。命令会重新调用 pybabel extract 和 pybabel update。

uv run autolang sync -d i18n --source ./src

Synchronization behavior:

同步行为：

• Newly added source strings: added to the po files for all locales
• Removed source strings: deleted from the po files for all locales
• Existing translations: kept unchanged

• 源码新增文案：添加到所有语言的 po 文件
• 源码删除文案：从所有语言的 po 文件删除
• 已有翻译：保持不变

Tagged translator comments placed immediately above gettext calls are also extracted into PO context during init and sync. Supported tags include NOTE, NOTES, TRANSLATOR, TRANSLATORS, I18N, L10N, LOCALIZATION, and LOC.

紧贴在 gettext 调用上方的带标签翻译注释，也会在 init 和 sync 期间被提取到 PO 上下文中。当前支持的标签包括 NOTE、NOTES、TRANSLATOR、TRANSLATORS、I18N、L10N、LOCALIZATION 和 LOC。

Scan untranslated text in po files, group entries by locale + source file, and then send them to the LLM in batches.

扫描 po 文件中的未翻译文本，按“语言 + 来源文件”分组，然后分批发送给大模型。

uv run autolang translate -d i18n --source ./src

You can also pass model settings explicitly:

也可以显式传入模型参数：

uv run autolang translate \
  -d i18n \
  --source ./src \
  --model deepseek-chat \
  --base-url https://api.deepseek.com \
  --api-key your-api-key

Translation behavior:

翻译行为：

• Process currently untranslated singular and plural entries
• Batch by source file to avoid mixing unrelated files in the same request
• Send already translated text from the same locale and source file as reference context
• Preserve technical content such as {name}, %(count)s, %s, code identifiers, paths, and CLI arguments
• No source language declaration is required, because text inside _() may be mixed-language; the model only needs to output the target-language version

• 处理当前未翻译的单数和复数条目
• 按来源文件分批，避免在同一次请求中混入无关文件
• 将同语言、同来源文件下已翻译的文本作为参考上下文传给模型
• 保留 {name}、%(count)s、%s、代码标识符、路径、CLI 参数等技术内容
• 不要求声明源语言，因为 _() 里的文本可能是混合语言；模型只需要输出目标语言版本

Common arguments:

常用参数：

• -d, --directory: Locale directory. Default: locales
• --source: Source-path hints. Can be passed multiple times
• --model: Model name
• --base-url: OpenAI-compatible API base URL
• --api-key: API key
• --batch-size: Maximum number of untranslated strings per request. Default: 50

• -d, --directory: 语言目录，默认 locales
• --source: 来源路径提示，可重复传入
• --model: 模型名
• --base-url: OpenAI 兼容接口地址
• --api-key: 接口密钥
• --batch-size: 单次请求最多发送多少条未翻译文本，默认 50

translate supports both command-line arguments and environment variables.

translate 同时支持命令行参数和环境变量。

Command-line arguments take priority. If they are not provided, Autolang falls back to the following environment variables:

命令行参数优先；如果未传入，则会回退到以下环境变量：

export AUTOLANG_MODEL=gpt-4.1-mini
export AUTOLANG_BASE_URL=https://your-openai-compatible-endpoint/v1
export AUTOLANG_API_KEY=your-api-key

The following variable names are also supported:

也兼容以下变量名：

export OPENAI_MODEL=gpt-4.1-mini
export OPENAI_BASE_URL=https://your-openai-compatible-endpoint/v1
export OPENAI_API_KEY=your-api-key

The project hides the gettext domain from end users, so -D/--domain is no longer exposed through the CLI.

项目对用户侧隐藏了 gettext domain，因此不再通过 CLI 暴露 -D/--domain。

Internally, it always reads from the DEFAULT_DOMAIN environment variable. If it is not set, messages is used by default.

内部统一从 DEFAULT_DOMAIN 环境变量读取；如果未设置，默认使用 messages。

export DEFAULT_DOMAIN=messages

If you really need another catalog filename, you can switch temporarily before running a command:

如果你确实需要另一套 catalog 文件名，可以在执行命令前临时切换：

DEFAULT_DOMAIN=backend uv run autolang init -d locales -l zh --source .

translate automatically looks for PROMPT.md under the directory passed to -d.

translate 会自动查找 -d 目录下的 PROMPT.md。

For example:

例如：

i18n/
  PROMPT.md
  messages.pot
  zh/LC_MESSAGES/messages.po

If the file exists, its content is appended to the default translation system prompt as additional instructions. This file is a good place for project glossaries, brand-name constraints, tone requirements, and similar guidance.

如果该文件存在，它的内容会作为额外说明追加到默认翻译系统提示词之后。这个文件适合放项目术语表、品牌名约束、语气风格要求等内容。

Example:

示例：

## Project-specific terminology

- `Autolang` is the project name. Do not translate or localize `Autolang`.
- Keep CLI flags such as `--source` unchanged.
- Prefer concise product UI wording.