# Example for validation of a config file

This example shows how to load and validate a user defined configuration file.
We use the two configuration dictionaries.
The first one represents a valid configuration, the second does not.

## Necessary imports


```python
from cattrs import ClassValidationError
```


```python
from baybe import Campaign
```

## Defining config dictionaries

Note that the following explicit call `str()` is not strictly necessary.
It is included since our method of converting this example to a markdown file does not
interpret this part of the code as `python` code if we do not include this call.


```python
CONFIG = str(
    """
{
    "searchspace": {
        "constructor": "from_product",
        "parameters": [
            {
                "type": "CategoricalParameter",
                "name": "Granularity",
                "values": [
                    "coarse",
                    "fine",
                    "ultra-fine"
                ],
                "encoding": "OHE"
            },
            {
                "type": "NumericalDiscreteParameter",
                "name": "Pressure[bar]",
                "values": [
                    1,
                    5,
                    10
                ],
                "tolerance": 0.2
            },
            {
                "type": "SubstanceParameter",
                "name": "Solvent",
                "data": {
                    "Solvent A": "COC",
                    "Solvent B": "CCCCC",
                    "Solvent C": "COCOC",
                    "Solvent D": "CCOCCOCCN"
                },
                "decorrelate": true,
                "encoding": "MORDRED"
            }
        ],
        "constraints": []
    },
    "objective": {
        "mode": "SINGLE",
        "targets": [
            {
                "type": "NumericalTarget",
                "name": "Yield",
                "mode": "MAX"
            }
        ]
    },
    "recommender": {
        "type": "TwoPhaseMetaRecommender",
        "initial_recommender": {
            "type": "FPSRecommender"
        },
        "recommender": {
            "type": "BotorchRecommender",
            "surrogate_model": {
                "type": "GaussianProcessSurrogate"
            },
            "acquisition_function": "qEI",
            "allow_repeated_recommendations": false,
            "allow_recommending_already_measured": false
        },
        "switch_after": 1
    }
}
"""
)
```


```python
INVALID_CONFIG = str(
    """
{
    "searchspace": {
        "constructor": "from_product",
        "parameters": [
            {
                "type": "INVALID_TYPE",
                "name": "Granularity",
                "values": [
                    "coarse",
                    "fine",
                    "ultra-fine"
                ],
                "encoding": "OHE"
            },
            {
                "type": "NumericalDiscreteParameter",
                "name": "Pressure[bar]",
                "values": [
                    1,
                    5,
                    10
                ],
                "tolerance": 0.2
            },
            {
                "type": "SubstanceParameter",
                "name": "Solvent",
                "data": {
                    "Solvent A": "COC",
                    "Solvent B": "CCCCC",
                    "Solvent C": "COCOC",
                    "Solvent D": "CCOCCOCCN"
                },
                "decorrelate": true,
                "encoding": "MORDRED"
            }
        ],
        "constraints": []
    },
    "objective": {
        "mode": "SINGLE",
        "targets": [
            {
                "type": "NumericalTarget",
                "name": "Yield",
                "mode": "MAX"
            }
        ]
    },
    "recommender": {
        "type": "TwoPhaseMetaRecommender",
        "initial_recommender": {
            "type": "FPSRecommender"
        },
        "recommender": {
            "type": "BotorchRecommender",
            "surrogate_model": {
                "type": "GaussianProcessSurrogate"
            },
            "acquisition_function": "qEI",
            "allow_repeated_recommendations": false,
            "allow_recommending_already_measured": false
        }
    }
}
"""
)
```

## Verification of the two dictionaries

The first validation should work.


```python
Campaign.validate_config(CONFIG)
print("The first config seems valid.")
```

    The first config seems valid.


    /Users/M290244/Programming/baybe_dev/.tox/docs-py310/lib/python3.10/site-
packages/baybe/objectives/deprecation.py:57: DeprecationWarning: An objective has been
specified without a corresponding type. Since 1 target(s) have been provided,
'SingleTargetObjective' is used as a fallback. However, this behavior is deprecated and
will be disabled in a future version.
      warnings.warn(
    /Users/M290244/Programming/baybe_dev/.tox/docs-py310/lib/python3.10/site-
packages/baybe/objective.py:18: DeprecationWarning: The use of `baybe.objective` is
deprecated and will be disabled in a future version. Use the classes defined in
`baybe.objectives` instead.
      warnings.warn(


This should fail.


```python
try:
    Campaign.validate_config(INVALID_CONFIG)
    campaign = Campaign.from_config(INVALID_CONFIG)
except ClassValidationError:
    print("Something is wrong with the second config, which is what we expected!")
```

    Something is wrong with the second config, which is what we expected!


    /Users/M290244/Programming/baybe_dev/.tox/docs-py310/lib/python3.10/site-
packages/baybe/objectives/deprecation.py:57: DeprecationWarning: An objective has been
specified without a corresponding type. Since 1 target(s) have been provided,
'SingleTargetObjective' is used as a fallback. However, this behavior is deprecated and
will be disabled in a future version.
      warnings.warn(
    /Users/M290244/Programming/baybe_dev/.tox/docs-py310/lib/python3.10/site-
packages/baybe/objective.py:18: DeprecationWarning: The use of `baybe.objective` is
deprecated and will be disabled in a future version. Use the classes defined in
`baybe.objectives` instead.
      warnings.warn(