# ＊ DomainBasedMapper

{% hint style="info" %}
**＊SDV Enterprise Feature.** This feature is available to our licensed users and is not currently in our public library. For more information, visit our page to [Explore SDV](https://docs.sdv.dev/sdv/explore/sdv-enterprise/compare-features).
{% endhint %}

The `DomainBasedMapper` creates and applies a consistent mapping between real emails and fake, synthetic emails. The mapping preserves the domain of the email. That is, emails belonging to a domain are mapped to fake emails in the same domain.

```python
from rdt.transformers.email import DomainBasedMapper

mapper = DomainBasedMapper()
```

## Parameters

**`preserved_domain`**: Which parts of the overall email domain to preserve during the transformation phase

<table data-header-hidden><thead><tr><th width="186"></th><th></th></tr></thead><tbody><tr><td>(default) <code>'full'</code></td><td>Preserve the full domain, which is everything after the <strong>@</strong> sign. For example if the email is <code>'info@datacebo.com'</code>, it will be mapped to a fake email that also ends with <code>'datacebo.com'</code>.</td></tr><tr><td><code>'top'</code></td><td>Extract only the top domain, which is everything after the <strong>.</strong> character. For example if the email is <code>'info@datacebo.com'</code>, it will be mapped a fake email that also ends with <code>'.com'</code>.</td></tr></tbody></table>

**`obfuscate_emails`**: Control whether the synthetic email looks realistic or follows random patterns.

<table data-header-hidden><thead><tr><th width="185"></th><th></th></tr></thead><tbody><tr><td>(default) <code>False</code></td><td>Create realistic-looking usernames and emails such as <code>'johndoe@gmail.com'</code>.</td></tr><tr><td><code>True</code></td><td>Obfuscate the usernames and emails to create random values such as <code>'dkep22ocp2@sdv-example.com'</code>.</td></tr></tbody></table>

{% hint style="warning" %}
Setting this to `False` may result in emails that correspond to real user emails by complete coincidence. If you are worried about creating emails that accidentally correspond to real users, please set this to`True`.
{% endhint %}

### Examples

```python
from rdt.transformers.email import DomainBasedMapper

mapper = DomainBasedMapper(
    preserved_domain='full',
    obfuscate_emails=True
)
```

## Attributes

After fitting the transformer, you can access the learned values through the attributes.

**`mapping`**: A dictionary that maps the original, real emails to the new, fake email

```python
>>> transformer.mapping
{
    'info@datacebo.com': 'dkep22ocp2@datacebo.com',
    'admissions@mit.edu': '9p3ocoo1pf@mit.edu',
    ...
}
```


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