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Generic Transformers

dict2graph comes with a lot of predefined transformers. For a basic concepts of a dict2Graph transformers have a look at How to use Transformers

Generic Transformers List

This is a list if transformers that can be applied to nodes and relationships

AddProperty

Bases: _RelationTransformerBase, _NodeTransformerBase

Add a property to a node Usage: 

from dict2graph import Dict2graph, Transformer, NodeTrans
from neo4j import GraphDatabase

NEO4J_DRIVER = GraphDatabase.driver("neo4j://localhost")

dic = {"person": {"name": "Camina"}}
d2g = Dict2graph()
d2g.add_node_transformation(
    Transformer.match_nodes("person").do(NodeTrans.AddProperty({"my_new_prop_key":"my_new_prop_value_1111"}))
    )
d2g.parse(dic)
d2g.create(NEO4J_DRIVER)
Results in a Neo4j node (:Person{name:'Camina',my_new_prop_key:"my_new_prop_value_1111"}).

Source code in dict2graph/transformers/generic_transformers.py 
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class AddProperty(_RelationTransformerBase, _NodeTransformerBase):
    """Add a property to a node
    Usage:
    ```python
    from dict2graph import Dict2graph, Transformer, NodeTrans
    from neo4j import GraphDatabase

    NEO4J_DRIVER = GraphDatabase.driver("neo4j://localhost")

    dic = {"person": {"name": "Camina"}}
    d2g = Dict2graph()
    d2g.add_node_transformation(
        Transformer.match_nodes("person").do(NodeTrans.AddProperty({"my_new_prop_key":"my_new_prop_value_1111"}))
        )
    d2g.parse(dic)
    d2g.create(NEO4J_DRIVER)
    ```
    Results in a Neo4j node `(:Person{name:'Camina',my_new_prop_key:"my_new_prop_value_1111"})`.
    """

    def __init__(self, properties: Dict):
        """_summary_

        Args:
            properties (Union[str, List[str]]): A property key or a list of property keys as strings that should be removed
        """
        if not isinstance(properties, dict):
            raise ValueError(
                f"Transformer `AddProperty` init failed. Parameters `properties` malformed: Expected dict, got {type(properties)}"
            )
        self.properties = properties

    def transform_node(self, node: Node):
        self._transform(node)

    def transform_rel(self, rel: Relation):
        self._transform(rel)

    def _transform(self, obj: Union[Node, Relation]):
        obj.update(self.properties)

__init__(properties)

summary

Parameters:

Name Type Description Default
properties Union[str, List[str]]

A property key or a list of property keys as strings that should be removed

 required
Source code in dict2graph/transformers/generic_transformers.py 
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def __init__(self, properties: Dict):
    """_summary_

    Args:
        properties (Union[str, List[str]]): A property key or a list of property keys as strings that should be removed
    """
    if not isinstance(properties, dict):
        raise ValueError(
            f"Transformer `AddProperty` init failed. Parameters `properties` malformed: Expected dict, got {type(properties)}"
        )
    self.properties = properties

EscapeInvalidNamesForNeo4JCompatibility

Bases: _RelationTransformerBase, _NodeTransformerBase

Non destructive escaping of labels and property keys to be valid with Neo4j rules

https://neo4j.com/docs/cypher-manual/current/syntax/naming/

Source code in dict2graph/transformers/generic_transformers.py 
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class EscapeInvalidNamesForNeo4JCompatibility(
    _RelationTransformerBase, _NodeTransformerBase
):
    """Non destructive escaping of labels and property keys to be valid with Neo4j rules
    # https://neo4j.com/docs/cypher-manual/current/syntax/naming/
    """

    def __init__(self):
        warn_message = "`dict2graph.RelTrans.EscapeInvalidNamesForNeo4JCompatibility` will propably fail because of https://github.com/kaiserpreusse/graphio/issues/10. Use dict2graph.RelTrans.SanitizeInvalidNamesForNeo4JCompatibility as workaround"
        log.warning(warn_message)

    def is_string_valid(self, val: str):

        if len(val) == 0:
            return False
        if not val[0].isalpha():
            return False
        elif not val.isalnum():
            return False
        elif len(val) > 65355:
            return False
        else:
            return True

    def make_valid(self, val: str):
        return f"`{val[:65354]}`"

    def _transform(self, obj: Dict):
        new_keys = {}
        for key in obj.keys():
            if not self.is_string_valid(key):
                new_keys[self.make_valid(key)] = obj[key]
        obj.update(new_keys)

    def transform_node(self, node: Node):
        new_labels = []
        for label in node.labels:
            if not self.is_string_valid(label):
                new_labels.append(self.make_valid(label))
            else:
                new_labels.append(label)
        node.labels = new_labels
        self._transform(node)

    def transform_rel(self, rel: Relation):
        if self.is_string_valid(rel.relation_type):
            rel.relation_type = self.make_valid(rel.relation_type)
        self._transform(rel)

OverridePropertyName

Bases: _RelationTransformerBase, _NodeTransformerBase

Replace a property name/key with a new string of your choice. Usage: 

from dict2graph import Dict2graph, Transformer, NodeTrans
from neo4j import GraphDatabase

NEO4J_DRIVER = GraphDatabase.driver("neo4j://localhost")

dic = {"person": {"name": "Camina Drummer"}}
d2g = Dict2graph()
d2g.add_node_transformation(
    Transformer.match_nodes("person").do(NodeTrans.OverridePropertyName("name","fullname"))
)
d2g.parse(dic)
d2g.create(NEO4J_DRIVER)
Results in a Neo4j node (:Person{fullname:'Camina Drummer'})

Source code in dict2graph/transformers/generic_transformers.py 
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class OverridePropertyName(_RelationTransformerBase, _NodeTransformerBase):
    """Replace a property name/key with a new string of your choice.
    Usage:
    ```python
    from dict2graph import Dict2graph, Transformer, NodeTrans
    from neo4j import GraphDatabase

    NEO4J_DRIVER = GraphDatabase.driver("neo4j://localhost")

    dic = {"person": {"name": "Camina Drummer"}}
    d2g = Dict2graph()
    d2g.add_node_transformation(
        Transformer.match_nodes("person").do(NodeTrans.OverridePropertyName("name","fullname"))
    )
    d2g.parse(dic)
    d2g.create(NEO4J_DRIVER)
    ```
    Results in a Neo4j node `(:Person{fullname:'Camina Drummer'})`
    """

    def __init__(self, source_property_name: str, target_property_name: str):
        """
        Args:
            source_property_name (str): The property key you want to be replaced.
            target_property_name (str): The The new name of the property.
        """
        self.source_property_name = source_property_name
        self.target_property_name = target_property_name

    def _transform(self, obj: Dict):
        if self.source_property_name in obj:
            obj[self.target_property_name] = obj.pop(self.source_property_name)

    def transform_node(self, node: Node):
        self._transform(node)

    def transform_rel(self, rel: Relation):
        self._transform(rel)

__init__(source_property_name, target_property_name)

Parameters:

Name Type Description Default
source_property_name str

The property key you want to be replaced.

 required
target_property_name str

The The new name of the property.

 required
Source code in dict2graph/transformers/generic_transformers.py 
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def __init__(self, source_property_name: str, target_property_name: str):
    """
    Args:
        source_property_name (str): The property key you want to be replaced.
        target_property_name (str): The The new name of the property.
    """
    self.source_property_name = source_property_name
    self.target_property_name = target_property_name

RemoveProperty

Bases: _RelationTransformerBase, _NodeTransformerBase

Remove a property from a node Usage: 

from dict2graph import Dict2graph, Transformer, NodeTrans
from neo4j import GraphDatabase

NEO4J_DRIVER = GraphDatabase.driver("neo4j://localhost")

dic = {"person": {"name": "Camina", "id":"sdf343"}}
d2g = Dict2graph()
d2g.add_node_transformation(
    Transformer.match_nodes("person").do(NodeTrans.RemoveProperty(id))
    )
d2g.parse(dic)
d2g.create(NEO4J_DRIVER)
Results in a Neo4j node (:Person{name:'Camina'}). the id property will be thrown away.

Source code in dict2graph/transformers/generic_transformers.py 
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class RemoveProperty(_RelationTransformerBase, _NodeTransformerBase):
    """Remove a property from a node
    Usage:
    ```python
    from dict2graph import Dict2graph, Transformer, NodeTrans
    from neo4j import GraphDatabase

    NEO4J_DRIVER = GraphDatabase.driver("neo4j://localhost")

    dic = {"person": {"name": "Camina", "id":"sdf343"}}
    d2g = Dict2graph()
    d2g.add_node_transformation(
        Transformer.match_nodes("person").do(NodeTrans.RemoveProperty(id))
        )
    d2g.parse(dic)
    d2g.create(NEO4J_DRIVER)
    ```
    Results in a Neo4j node `(:Person{name:'Camina'})`. the `id` property will be thrown away.
    """

    def __init__(self, property_keys: Union[str, List[str]]):
        """_summary_

        Args:
            property_keys (Union[str, List[str]]): A property key or a list of property keys as strings that should be removed
        """
        if isinstance(property_keys, str):
            property_keys = [property_keys]
        self.property_keys = property_keys

    def custom_node_match(self, node: Node) -> bool:
        # check if node keys and defined properties have an overlap
        return not set(self.property_keys).isdisjoint(set(node.keys()))

    def transform_node(self, node: Node):
        self._transform(node)

    def transform_rel(self, rel: Relation):
        self._transform(rel)

    def _transform(self, obj: Union[Node, Relation]):
        for prop in self.property_keys:
            obj.pop(prop, None)

__init__(property_keys)

summary

Parameters:

Name Type Description Default
property_keys Union[str, List[str]]

A property key or a list of property keys as strings that should be removed

 required
Source code in dict2graph/transformers/generic_transformers.py 
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def __init__(self, property_keys: Union[str, List[str]]):
    """_summary_

    Args:
        property_keys (Union[str, List[str]]): A property key or a list of property keys as strings that should be removed
    """
    if isinstance(property_keys, str):
        property_keys = [property_keys]
    self.property_keys = property_keys

SanitizeInvalidNamesForNeo4JCompatibility

Bases: _RelationTransformerBase, _NodeTransformerBase

Destructive renaming of labels and property keys to be valid with Neo4j rules

https://neo4j.com/docs/cypher-manual/current/syntax/naming/

Usage: 

from dict2graph import Dict2graph, Transformer, NodeTrans
from neo4j import GraphDatabase

NEO4J_DRIVER = GraphDatabase.driver("neo4j://localhost")

dic = {"$person": {"1name": "Camina Drummer"}}
d2g = Dict2graph()
d2g.add_node_transformation(
    Transformer.match_nodes().do(NodeTrans.SanitizeInvalidNamesForNeo4JCompatibility("name","fullname"))
)
d2g.parse(dic)
d2g.create(NEO4J_DRIVER)
Results in a Neo4j node (:Person{name:'Camina Drummer'})

Source code in dict2graph/transformers/generic_transformers.py 
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class SanitizeInvalidNamesForNeo4JCompatibility(
    _RelationTransformerBase, _NodeTransformerBase
):
    """Destructive renaming of labels and property keys to be valid with Neo4j rules

    https://neo4j.com/docs/cypher-manual/current/syntax/naming/

    Usage:
    ```python
    from dict2graph import Dict2graph, Transformer, NodeTrans
    from neo4j import GraphDatabase

    NEO4J_DRIVER = GraphDatabase.driver("neo4j://localhost")

    dic = {"$person": {"1name": "Camina Drummer"}}
    d2g = Dict2graph()
    d2g.add_node_transformation(
        Transformer.match_nodes().do(NodeTrans.SanitizeInvalidNamesForNeo4JCompatibility("name","fullname"))
    )
    d2g.parse(dic)
    d2g.create(NEO4J_DRIVER)
    ```
    Results in a Neo4j node `(:Person{name:'Camina Drummer'})`
    """

    def is_string_valid(self, val: str):

        if len(val) == 0:
            return False
        if not val[0].isalpha():
            return False
        elif not val.isalnum():
            return False
        elif len(val) > 65355:
            return False
        else:
            return True

    def make_valid(self, val: str):
        result = ""
        result_appendix = ""
        starts_with_alpha: bool = False
        for index, c in enumerate(val):
            if index > 65353:
                break
            if not starts_with_alpha and c.isnumeric():
                result_appendix += c
                continue
            elif not starts_with_alpha and c.isalpha():
                starts_with_alpha = True
            if c == "-":
                result += "_"
                continue
            if c.isalnum():
                result += c
        return result

    def _transform(self, obj: Dict):
        new_props = {}
        del_keys = []
        for key in obj.keys():
            if not self.is_string_valid(key):
                new_props[self.make_valid(key)] = obj[key]
                del_keys.append(key)
        for k in del_keys:
            del obj[k]
        obj.update(new_props)

    def transform_node(self, node: Node):
        new_labels = []
        for label in node.labels:
            if not self.is_string_valid(label):
                new_labels.append(self.make_valid(label))
            else:
                new_labels.append(label)
        node.labels = new_labels
        self._transform(node)

    def transform_rel(self, rel: Relation):
        if not self.is_string_valid(rel.relation_type):
            rel.relation_type = self.make_valid(rel.relation_type)
        self._transform(rel)

TypeCastProperty

Bases: _RelationTransformerBase, _NodeTransformerBase

change the type of property values. Usage: 

from dict2graph import Dict2graph, Transformer, NodeTrans
from neo4j import GraphDatabase

NEO4J_DRIVER = GraphDatabase.driver("neo4j://localhost")

dic = {"person": {"name": "Camina", "captain":"true", "age":"39"}}
d2g = Dict2graph()
d2g.add_node_transformation([
    Transformer.match_nodes("person").do(NodeTrans.TypeCastProperty("captain",bool)),
    Transformer.match_nodes("person").do(NodeTrans.TypeCastProperty("age",int)),
])
d2g.parse(dic)
d2g.create(NEO4J_DRIVER)
Results in a Neo4j node (:Person{name:'Camina',captain:true,age:27})

Source code in dict2graph/transformers/generic_transformers.py 
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class TypeCastProperty(_RelationTransformerBase, _NodeTransformerBase):
    """change the type of property values.
    Usage:
    ```python
    from dict2graph import Dict2graph, Transformer, NodeTrans
    from neo4j import GraphDatabase

    NEO4J_DRIVER = GraphDatabase.driver("neo4j://localhost")

    dic = {"person": {"name": "Camina", "captain":"true", "age":"39"}}
    d2g = Dict2graph()
    d2g.add_node_transformation([
        Transformer.match_nodes("person").do(NodeTrans.TypeCastProperty("captain",bool)),
        Transformer.match_nodes("person").do(NodeTrans.TypeCastProperty("age",int)),
    ])
    d2g.parse(dic)
    d2g.create(NEO4J_DRIVER)
    ```
    Results in a Neo4j node `(:Person{name:'Camina',captain:true,age:27})`
    """

    def __init__(self, property_name: str, target_type: Union[str, int, float, bool]):
        """
        Args:
            property_name (str): The property key that should be changed
            target_type (Union[str, int, float, bool]): The type that should result
        """
        self.property_name = property_name
        self.target_type = target_type

    def _transform(self, obj: Dict):
        if self.property_name in obj:
            if self.target_type == bool:
                obj[self.property_name] = True
                if obj[self.property_name] in [
                    0,
                    "0",
                    None,
                    "Null",
                    "false",
                    "False",
                    "f",
                    "F",
                    "No",
                    "no",
                ]:
                    obj[self.property_name] = False
            else:
                obj[self.property_name] = self.target_type(obj[self.property_name])

    def transform_node(self, node: Node):
        self._transform(node)

    def transform_rel(self, rel: Relation):
        self._transform(rel)

__init__(property_name, target_type)

Parameters:

Name Type Description Default
property_name str

The property key that should be changed

 required
target_type Union[str, int, float, bool]

The type that should result

 required
Source code in dict2graph/transformers/generic_transformers.py 
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def __init__(self, property_name: str, target_type: Union[str, int, float, bool]):
    """
    Args:
        property_name (str): The property key that should be changed
        target_type (Union[str, int, float, bool]): The type that should result
    """
    self.property_name = property_name
    self.target_type = target_type