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https://github.com/david-lor/python-classmapper

A simple class mapping (conversion) Python library
https://github.com/david-lor/python-classmapper

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A simple class mapping (conversion) Python library

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# Python ClassMapper

A simple class mapping (conversion) Python library.

## Example

Imagine you have two classes, `OriginCls` and `DestinationCls`:

```python
from dataclasses import dataclass

@dataclass
class OriginCls:
id: str
name: str
age: int

@dataclass
class DestinationCls:
_id: str
data: dict
```

You want to be able to convert an object of `OriginCls` to `DestinationCls` and viceversa.
ClassMapper allows you to define "mappers" - functions that explicitly convert an object of a class A to a new instance of a class B.
Being explicit means that you have to explicitly define how the conversion between classes is performed.

```python
from classmapper import ClassMapper

mapper = ClassMapper()

@mapper.register(OriginCls, DestinationCls)
def _mapper_origin_destination(_from: OriginCls) -> DestinationCls:
return DestinationCls(
_id=_from.id,
data={
"name": _from.name,
"age": _from.age
}
)

@mapper.register(DestinationCls, OriginCls)
def _mapper_destination_origin(_from: DestinationCls) -> OriginCls:
return OriginCls(
id=_from._id,
name=_from.data["name"],
age=_from.data["age"]
)
```

Now you can convert an object of `OriginCls` into `DestinationCls`, and viceversa:

```python
source = OriginCls(id="1", name="foo", age=21)
# mapper.map(source object, target class)
# returns object of target class, if a mapper between source object's class and target class is registered
result = mapper.map(source, DestinationCls)
print(result)

# convert back into the original
result = mapper.map(result, OriginCls)
print(result)
```

If you try to convert between classes not mapped, a NoClassMappingError is raised:

```python
class OtherCls:
pass

mapper.map(source, OtherCls) # raises NoClassMappingError
```

More examples can be found on [tests](tests).