# python: t
URL: https://generaltranslation.com/en-US/docs/python/api/t.mdx
---
title: t
description: API reference for the t translation function
---

## Overview

The `t` function translates and interpolates an ICU MessageFormat string.
It looks up the current locale, finds a cached translation by hash, and interpolates variables.
If no translation is found, it falls back to the source string.

```python
from gt_flask import t  # or from gt_fastapi import t

message = t("Hello, {name}!", name="World")
```

## Reference

### Parameters

<TypeTable
  type={{
    "message": {
      type: 'str',
      description: 'The ICU MessageFormat source string.',
    },
    "**kwargs": {
      type: 'object',
      description: 'Interpolation variables and GT options.',
    },
  }}
/>

### GT options (passed via `**kwargs`)

| Option | Type | Description |
| ------ | ---- | ----------- |
| `_context` | `str` | Additional context to disambiguate translations with the same source text. |
| `_id` | `str` | Custom identifier for the translation entry. |
| `_max_chars` | `int` | Maximum character length for the output. |

### Returns

`str` — the translated and interpolated string.

---

## Examples

### Simple translation

```python
t("Hello, world!")
```

### With variables

```python
t("Hello, {name}!", name="Alice")
```

### With context

```python
t("Bank", _context="financial institution")
t("Bank", _context="river bank")
```

### With f-strings and `declare_var`

Python f-strings work naturally with `t` — just wrap your variables with [`declare_var`](/docs/python/api/declare-var):

```python
from gt_flask import t, declare_var

# Before i18n:
message = f"{name} goes home"

# After i18n — just wrap with t() and declare_var():
message = t(f"{declare_var(name, name='name')} goes home")
```

### With character limit

```python
t("This is a very long message that might need truncation", _max_chars=20)
```

---

## Notes

- `t` requires [`initialize_gt`](/docs/python/api/initialize-gt) to be called first.
- If the current locale matches the default locale, no translation lookup is performed — only interpolation.
- Variables are interpolated using ICU MessageFormat syntax (e.g., `{name}`, `{count, plural, one {# item} other {# items}}`).