## Mapper


A data mapper.


Usage


``` python
Mapper(mapping)
```


## Parameters


`mapping: dict`  
A dictionary mapping keys to values.


## Methods

| Name | Description |
|----|----|
| [apply()](#apply) | Look up a key in the mapping. |
| [keys()](#keys) | Get all keys. |

------------------------------------------------------------------------


#### apply()


Look up a key in the mapping.


Usage


``` python
apply(key)
```


##### Parameters


`key: str`  
The key to look up.


##### Returns


`object`  
The mapped value.


------------------------------------------------------------------------


#### keys()


Get all keys.


Usage


``` python
keys()
```


##### Returns


`list`  
All mapping keys.