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# Payment

The `pydantic_extra_types.payment` module provides the [`PaymentCardNumber`](/guides/pydantic-extra-types-pydantic-extra-types-payment#paymentcardnumber) data type.

## PaymentCardBrand

**Bases:** [`str`](https://docs.python.org/3/builtins/stdtypes.html#str), `Enum`

Payment card brands supported by the [`PaymentCardNumber`](/guides/pydantic-extra-types-pydantic-extra-types-payment#paymentcardnumber).

## PaymentCardNumber

**Bases:** [`str`](https://docs.python.org/3/builtins/stdtypes.html#str)

A [payment card number](https://en.wikipedia.org/wiki/Payment_card_number).

### Attributes

#### strip\_whitespace

Whether to strip whitespace from the input value.

**Type:** [`bool`](https://docs.python.org/3/builtins/functions.html#bool) **Default:** `True`

#### min\_length

The minimum length of the card number.

**Type:** [`int`](https://docs.python.org/3/builtins/functions.html#int) **Default:** `12`

#### max\_length

The maximum length of the card number.

**Type:** [`int`](https://docs.python.org/3/builtins/functions.html#int) **Default:** `19`

#### bin

The first 6 digits of the card number.

**Type:** [`str`](https://docs.python.org/3/builtins/stdtypes.html#str) **Default:** `card_number[:6]`

#### last4

The last 4 digits of the card number.

**Type:** [`str`](https://docs.python.org/3/builtins/stdtypes.html#str) **Default:** `card_number[(-4):]`

#### brand

The brand of the card.

**Type:** `PaymentCardBrand` **Default:** `self.validate_brand(card_number)`

#### masked

The masked card number.

**Type:** [`str`](https://docs.python.org/3/builtins/stdtypes.html#str)

### Methods

#### validate

`@classmethod`

```python
def validate(
    cls,
    __input_value: str,
    _: core_schema.ValidationInfo,
) -> PaymentCardNumber
```

Validate the `PaymentCardNumber` instance.

##### Returns

[`PaymentCardNumber`](/guides/pydantic-types#paymentcardnumber) -- The validated `PaymentCardNumber` instance.

##### Parameters

**`__input_value`** : [`str`](https://docs.python.org/3/builtins/stdtypes.html#str)

The input value to validate.

**`_`** : `core_schema.ValidationInfo`

The validation info.

#### validate\_digits

`@classmethod`

```python
def validate_digits(cls, card_number: str) -> None
```

Validate that the card number is all digits.

##### Returns

[`None`](https://docs.python.org/3/builtins/constants.html#None)

##### Parameters

**`card_number`** : [`str`](https://docs.python.org/3/builtins/stdtypes.html#str)

The card number to validate.

##### Raises

- `PydanticCustomError` -- If the card number is not all digits.

#### validate\_luhn\_check\_digit

`@classmethod`

```python
def validate_luhn_check_digit(cls, card_number: str) -> str
```

Validate the payment card number. Based on the [Luhn algorithm](https://en.wikipedia.org/wiki/Luhn_algorithm).

##### Returns

[`str`](https://docs.python.org/3/builtins/stdtypes.html#str) -- The validated card number.

##### Parameters

**`card_number`** : [`str`](https://docs.python.org/3/builtins/stdtypes.html#str)

The card number to validate.

##### Raises

- `PydanticCustomError` -- If the card number is not valid.

#### validate\_brand

`@staticmethod`

```python
def validate_brand(card_number: str) -> PaymentCardBrand
```

Validate length based on \[BIN]\(https://en.wikipedia.org/wiki/Payment_card_number#Issuer_identification_number_(IIN\)) for major brands.

##### Returns

`PaymentCardBrand` -- The validated card brand.

##### Parameters

**`card_number`** : [`str`](https://docs.python.org/3/builtins/stdtypes.html#str)

The card number to validate.

##### Raises

- `PydanticCustomError` -- If the card number is not valid.

## Related pages

- [API Documentation](./api-documentation-index.md)
- [Concepts](./concepts-index.md)
- [Dev Tools](./dev-tools-index.md)
- [Error Messages](./error-messages-index.md)
- [Examples](./examples-index.md)
- [Integrations](./integrations-index.md)
- [Internals](./internals-index.md)
- [Production Tools](./production-tools-index.md)
- [Pydantic](./pydantic-index.md)
- [Pydantic Core](./pydantic-core-index.md)

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