# General Translation Python SDKs: derive
URL: https://generaltranslation.com/en-US/docs/python/reference/functions/derive.mdx
---

title: derive
description: Mark content with a finite set of variants for build-time extraction in General Translation Python. API reference for derive.

---

Marks content as statically analyzable so the General Translation CLI can extract every possible translation entry at build time. It is an identity function — it returns exactly what you pass in — used purely as a marker.

## Overview [#overview]

Wrap a static expression that has a finite set of possible values with `derive`, typically inside a [`t`](/docs/python/reference/functions/t) call. At runtime `derive` returns its input unchanged; at extraction time the CLI generates a translation entry for each outcome.

```python
from gt_flask import derive, t  # or: from gt_fastapi, or: from gt_i18n

message = t(f"The {derive('boy' if gender == 'male' else 'girl')} is playing.")
```

Signature:

```python
derive(content: object) -> object
```

Re-exported from `generaltranslation.static` by `gt_i18n` and the framework packages. See [Declaring variables and variants](/docs/python/guides/declaring-variables) for usage patterns.

## How it works [#how-it-works]

- **Identity at runtime.** It returns `content` unchanged; its only purpose is to mark content for the CLI.
- **Static analysis.** All possible outcomes must be statically analyzable at build time so the CLI can generate an entry for each.
- **Dynamic values.** Wrap dynamic content inside a derived sentence with [`declare_var`](/docs/python/reference/functions/declare-var).

## Parameters [#parameters]

| Parameter | Description | Type | Optional | Default |
| --- | --- | --- | --- | --- |
| [`content`](#content) | A static expression with a finite set of possible values. | `object` | No | — |

### `content` [#content]

**Type** `object` · **Required**

A static expression with a finite set of possible values.

## Returns [#returns]

**Type** `object`

Returns `content` unchanged. The function is an identity marker for the CLI.

## Example [#example]

```python
from gt_flask import t, derive, declare_var

t(f"{declare_var(name, name='name')} adopted a {derive('cat' if is_cat else 'dog')}.")
```

*Note: [`declare_static`](/docs/python/reference/functions/declare-static) is a deprecated alias for `derive`. Use `derive` in new code.*