marshmallow-enum 1.4

Enum field for Marshmallow

# marshmallow-enum

Enum field for use with Marshmallow.

## Installation

```bash
pip install --user marshmallow_enum
```

If you're on a version before 3.4, you'll also need to install `enum34`.

## Using The Field

To make use of the field, you must have an existing Enum:

```python
from enum import Enum


class StopLight(Enum):
green = 1
yellow = 2
red = 3
```

Then, declare it as a field in a schema:

```python
from marshmallow import Schema
from marshmallow_enum import EnumField


class TrafficStop(Schema):
light_color = EnumField(StopLight)
```

By default, the field will load and dump based on the _name_ given to an enum value.

```python
schema = TrafficStop()
schema.dump({'light_color': EnumField.red}).data
# {'light_color': 'red'}

schema.load({'light_color': 'red'}).data
# {'light_color': EnumField.red}
```

### Customizing loading and dumping behavior

To customize how an enum is serialized or deserialized, there are three options:

- Setting `by_value=True`. This will cause both dumping and loading to use the value of the enum.
- Setting `load_by=EnumField.VALUE`. This will cause loading to use the value of the enum.
- Setting `dump_by=EnumField.VALUE`. This will cause dumping to use the value of the enum.

If either `load_by` or `dump_by` are unset, they will follow from `by_value`.

Additionally, there is `EnumField.NAME` to be explicit about the load and dump behavior, this
is the same as leaving both `by_value` and either `load_by` and/or `dump_by` unset.

### Custom Error Message

A custom error message can be provided via the `error` keyword argument. It can accept three
format values:

- `{input}`: The value provided to the schema field
- `{names}`: The names of the individual enum members
- `{values}`: The values of the individual enum members

Previously, the following inputs were also available but are deprecated and will be removed in 1.6:

- `{name}`
- `{value}`
- `{choices}`


Version 1.4
===========

* Deprecate the `{choices}`, `{name}` and `{value}` format keys for custom error messages
* Allow configure loading and dumping independently