## build_value_map()


Create a pysdmx ValueMap object mapping a source value to a target value.


Usage

``` python
build_value_map(
    source,
    target,
    valid_from=None,
    valid_to=None,
)
```


## Parameters


`source: str`  
The source value to map.

`target: str`  
The target value to map to.

`valid_from: datetime | None = None`  
Start of business validity for the mapping.

`valid_to: datetime | None = None`  
End of business validity for the mapping.


## Returns


`ValueMap`  
A pysdmx ValueMap object representing the mapping.


## Raises


`ValueError`  
If source or target is empty.

`TypeError`  
If source or target is not a string.


## Examples


``` python
    >>> from datetime import datetime
    >>> vm = build_value_map("BE", "BEL")
    >>> isinstance(vm, ValueMap)
```

    True

``` python
    >>> vm.source
```

    'BE'

``` python
    >>> vm.target
```

    'BEL'

``` python
    >>> vm2 = build_value_map("DE", "GER", valid_from=datetime(2020, 1, 1))
    >>> vm2.valid_from.year
```

    2020