Edge Functions

Functions to upsert, retrieve and delete edges. All functions in this module are called as methods on a TigerGraphConnection object.

getEdgeTypes()

getEdgeTypes(force: bool = False) → list

Returns the list of edge type names of the graph.

Parameter:

  • force: If True, forces the retrieval the schema metadata again, otherwise returns a cached copy of edge type metadata (if they were already fetched previously).

Returns:

The list of edge types defined in the current graph.

getEdgeType()

getEdgeType(edgeType: str, force: bool = False) → dict

Returns the details of the edge type.

Parameters:

  • edgeType: The name of the edge type.

  • force: If True, forces the retrieval the schema details again, otherwise returns a cached copy of edge type details (if they were already fetched previously).

Returns:

The metadata of the edge type.

getEdgeSourceVertexType()

getEdgeSourceVertexType(edgeType: str) → Union[str, set]

Returns the type(s) of the edge type’s source vertex.

Parameter:

  • edgeType: The name of the edge type.

Returns:

  • A single source vertex type name string if the edge has a single source vertex type.

  • "*" if the edge can originate from any vertex type (notation used in 2.6.1 and earlier versions).
    See the documentation for more details.

  • A set of vertex type name strings (unique values) if the edge has multiple source vertex types (notation used in 3.0 and later versions).
    Even if the source vertex types were defined as "*", the REST API will list them as pairs (i.e. not as "*" in 2.6.1 and earlier versions), just like as if there were defined one by one (e.g. FROM v1, TO v2 | FROM v3, TO v4 | …).

The returned set contains all source vertex types, but it does not certainly mean that the edge is defined between all source and all target vertex types. You need to look at the individual source/target pairs to find out which combinations are valid/defined.

getEdgeTargetVertexType()

getEdgeTargetVertexType(edgeType: str) → Union[str, set]

Returns the type(s) of the edge type’s target vertex.

Parameter:

  • edgeType: The name of the edge type.

Returns:

  • A single target vertex type name string if the edge has a single target vertex type.

  • "*" if the edge can end in any vertex type (notation used in 2.6.1 and earlier versions).
    See the documentation for more details.

  • A set of vertex type name strings (unique values) if the edge has multiple target vertex types (notation used in 3.0 and later versions).
    Even if the target vertex types were defined as "*", the REST API will list them as pairs (i.e. not as "*" in 2.6.1 and earlier versions), just like as if there were defined one by one (e.g. FROM v1, TO v2 | FROM v3, TO v4 | …).

The returned set contains all target vertex types, but does not certainly mean that the edge is defined between all source and all target vertex types. You need to look at the individual source/target pairs to find out which combinations are valid/defined.

isDirected()

isDirected(edgeType: str) → bool

Is the specified edge type directed?

Parameter:

  • edgeType: The name of the edge type.

Returns:

True, if the edge is directed.

getReverseEdge()

getReverseEdge(edgeType: str) → str

Returns the name of the reverse edge of the specified edge type, if applicable.

Parameter:

  • edgeType: The name of the edge type.

Returns:

The name of the reverse edge, if it was defined.

getEdgeCountFrom()

getEdgeCountFrom(sourceVertexType: str = "", sourceVertexId: Union[str, int] = None, edgeType: str = "", targetVertexType: str = "", targetVertexId: Union[str, int] = None, where: str = "") → dict

Returns the number of edges from a specific vertex.

Parameters:

  • sourceVertexType: The name of the source vertex type.

  • sourceVertexId: The primary ID value of the source vertex instance.

  • edgeType: The name of the edge type.

  • targetVertexType: The name of the target vertex type.

  • targetVertexId: The primary ID value of the target vertex instance.

  • where: A comma separated list of conditions that are all applied on each edge’s attributes. The conditions are in logical conjunction (i.e. they are "AND’ed" together).

Returns:

A dictionary of edge_type: edge_count pairs.

Uses:

  • If edgeType = "*": edge count of all edge types (no other arguments can be specified in this case).

  • If edgeType is specified only: edge count of the given edge type.

  • If sourceVertexType, edgeType, targetVertexType are specified: edge count of the given edge type between source and target vertex types.

  • If sourceVertexType, sourceVertexId are specified: edge count of all edge types from the given vertex instance.

  • If sourceVertexType, sourceVertexId, edgeType are specified: edge count of all edge types from the given vertex instance.

  • If sourceVertexType, sourceVertexId, edgeType, where are specified: the edge count of the given edge type after filtered by where condition.

  • If targetVertexId is specified, then targetVertexType must also be specified.

  • If targetVertexType is specified, then edgeType must also be specified.

Endpoints:

  • GET /graph/{graph_name}/edges/{source_vertex_type}/{source_vertex_id}
    See the documentation for more details.

  • POST /builtins/{graph_name}
    See the documentation for more details.

getEdgeCount()

getEdgeCount(edgeType: str = "*", sourceVertexType: str = "", targetVertexType: str = "") → dict

Returns the number of edges of an edge type.

This is a simplified version of getEdgeCountFrom(), to be used when the total number of edges of a given type is needed, regardless which vertex instance they are originated from. See documentation of getEdgeCountFrom above for more details.

Parameters:

  • edgeType: The name of the edge type.

  • sourceVertexType: The name of the source vertex type.

  • targetVertexType: The name of the target vertex type.

Returns:

A dictionary of edge_type: edge_count pairs.

upsertEdge()

upsertEdge(sourceVertexType: str, sourceVertexId: str, edgeType: str, targetVertexType: str, targetVertexId: str, attributes: dict = None) → int

Upserts an edge.

Data is upserted:

  • If edge is not yet present in graph, it will be created (see special case below).

  • If it’s already in the graph, it is updated with the values specified in the request.

  • If vertex_must_exist is True then edge will only be created if both vertex exists in graph. Otherwise missing vertices are created with the new edge; the newly created vertices' attributes (if any) will be created with default values.

Parameters:

  • sourceVertexType: The name of the source vertex type.

  • sourceVertexId: The primary ID value of the source vertex instance.

  • edgeType: The name of the edge type.

  • targetVertexType: The name of the target vertex type.

  • targetVertexId: The primary ID value of the target vertex instance.

  • attributes: A dictionary in this format:

    {<attribute_name>, <attribute_value>|(<attribute_name>, <operator>), …}

    Example:

    {"visits": (1482, "+"), "max_duration": (371, "max")}

For valid values of <operator> see the documentation .

Returns:

A single number of accepted (successfully upserted) edges (0 or 1).

Endpoint:

  • POST /graph/{graph_name}
    See the documentation for more details.

upsertEdges()

upsertEdges(sourceVertexType: str, edgeType: str, targetVertexType: str, edges: list) → int

Upserts multiple edges (of the same type).

Parameters:

  • sourceVertexType: The name of the source vertex type.

  • edgeType: The name of the edge type.

  • targetVertexType: The name of the target vertex type.

  • edges: A list in of tuples in this format:

    [
        (<source_vertex_id>, <target_vertex_id>, {<attribute_name>: <attribute_value>, …}),
        (<source_vertex_id>, <target_vertex_id>, {<attribute_name>: (<attribute_value>, <operator>), …})
        ⋮
    ]

    Example:

    [
        (17, "home_page", {"visits": (35, "+"), "max_duration": (93, "max")}),
        (42, "search", {"visits": (17, "+"), "max_duration": (41, "max")})
    ]

For valid values of <operator> see the documentation .

Returns:

A single number of accepted (successfully upserted) edges (0 or positive integer).

Endpoint:

  • POST /graph/{graph_name}
    See the documentation for more details.

upsertEdgeDataFrame()

upsertEdgeDataFrame(df: pd.DataFrame, sourceVertexType: str, edgeType: str, targetVertexType: str, from_id: str = "", to_id: str = "", attributes: dict = None) → int

Upserts edges from a Pandas DataFrame.

Parameters:

  • df: The DataFrame to upsert.

  • sourceVertexType: The type of source vertex for the edge.

  • edgeType: The type of edge to upsert data to.

  • targetVertexType: The type of target vertex for the edge.

  • from_id: The field name where the source vertex primary id is given. If omitted, the dataframe index would be used instead.

  • to_id: The field name where the target vertex primary id is given. If omitted, the dataframe index would be used instead.

  • attributes: A dictionary in the form of {target: source} where source is the column name in the dataframe and target is the attribute name in the graph vertex. When omitted, all columns would be upserted with their current names. In this case column names must match the vertex’s attribute names.

Returns:

The number of edges upserted.

getEdges()

getEdges(sourceVertexType: str, sourceVertexId: str, edgeType: str = "", targetVertexType: str = "", targetVertexId: str = "", select: str = "", where: str = "", limit: Union[int, str] = None, sort: str = "", fmt: str = "py", withId: bool = True, withType: bool = False, timeout: int = 0) → Union[dict, str, pd.DataFrame]

Retrieves edges of the given edge type originating from a specific source vertex.

Only sourceVertexType and sourceVertexId are required. If targetVertexId is specified, then targetVertexType must also be specified. If targetVertexType is specified, then edgeType must also be specified.

Parameters:

  • sourceVertexType: The name of the source vertex type.

  • sourceVertexId: The primary ID value of the source vertex instance.

  • edgeType: The name of the edge type.

  • targetVertexType: The name of the target vertex type.

  • targetVertexId: The primary ID value of the target vertex instance.

  • select: Comma separated list of edge attributes to be retrieved or omitted.

  • where: Comma separated list of conditions that are all applied on each edge’s attributes. The conditions are in logical conjunction (i.e. they are "AND’ed" together).

  • sort: Comma separated list of attributes the results should be sorted by.

  • limit: Maximum number of edge instances to be returned (after sorting).

  • fmt: Format of the results returned:

    • "py": Python objects

    • "json": JSON document

    • "df": pandas DataFrame

  • withId: (When the output format is "df") Should the source and target vertex types and IDs be included in the dataframe?

  • withType: (When the output format is "df") Should the edge type be included in the dataframe?

  • timeout: Time allowed for successful execution (0 = no time limit, default).

Returns:

The (selected) details of the (matching) edge instances (sorted, limited) as dictionary, JSON or pandas DataFrame.

Endpoint:

  • GET /graph/{graph_name}/edges/{source_vertex_type}/{source_vertex_id}
    See the documentation for more details.

getEdgesDataFrame()

getEdgesDataFrame(sourceVertexType: str, sourceVertexId: str, edgeType: str = "", targetVertexType: str = "", targetVertexId: str = "", select: str = "", where: str = "", limit: str = "", sort: str = "", timeout: int = 0) → pd.DataFrame

Retrieves edges of the given edge type originating from a specific source vertex.

This is a shortcut to getEdges(…​, fmt="df", withId=True, withType=False). Only sourceVertexType and sourceVertexId are required. If targetVertexId is specified, then targetVertexType must also be specified. If targetVertexType is specified, then edgeType must also be specified.

Parameters:

  • sourceVertexType: The name of the source vertex type.

  • sourceVertexId: The primary ID value of the source vertex instance.

  • edgeType: The name of the edge type.

  • targetVertexType: The name of the target vertex type.

  • targetVertexId: The primary ID value of the target vertex instance.

  • select: Comma separated list of edge attributes to be retrieved or omitted.

  • where: Comma separated list of conditions that are all applied on each edge’s attributes. The conditions are in logical conjunction (i.e. they are "AND’ed" together).

  • sort: Comma separated list of attributes the results should be sorted by.

  • limit: Maximum number of edge instances to be returned (after sorting).

  • timeout: Time allowed for successful execution (0 = no limit, default).

Returns:

The (selected) details of the (matching) edge instances (sorted, limited) as dictionary, JSON or pandas DataFrame.

getEdgesDataframe()

getEdgesDataframe(sourceVertexType: str, sourceVertexId: str, edgeType: str = "", targetVertexType: str = "", targetVertexId: str = "", select: str = "", where: str = "", limit: str = "", sort: str = "", timeout: int = 0) → pd.DataFrame

DEPRECATED

Use getEdgesDataFrame() instead.

getEdgesByType()

getEdgesByType(edgeType: str, fmt: str = "py", withId: bool = True, withType: bool = False) → Union[dict, str, pd.DataFrame]

Retrieves edges of the given edge type regardless the source vertex.

Parameters:

  • edgeType: The name of the edge type.

  • fmt: Format of the results returned:

    • "py": Python objects

    • "json": JSON document

    • "df": pandas DataFrame

  • withId: (When the output format is "df") Should the source and target vertex types and IDs be included in the dataframe?

  • withType: (When the output format is "df") should the edge type be included in the dataframe?

Returns:

The details of the edge instances of the given edge type as dictionary, JSON or pandas DataFrame.

getEdgeStats()

getEdgeStats(edgeTypes: Union[str, list], skipNA: bool = False) → dict

Returns edge attribute statistics.

Parameters:

  • edgeTypes: A single edge type name or a list of edges types names or '*' for all edges types.

  • skipNA: Skip those edges that do not have attributes or none of their attributes have statistics gathered.

Returns:

Attribute statistics of edges; a dictionary of dictionaries.

Endpoint:

  • POST /builtins/{graph_name}
    See the documentation for more details.

delEdges()

delEdges(sourceVertexType: str, sourceVertexId: str, edgeType: str = "", targetVertexType: str = "", targetVertexId: str = "", where: str = "", limit: str = "", sort: str = "", timeout: int = 0) → dict

Deletes edges from the graph.

Only sourceVertexType and sourceVertexId are required. If targetVertexId is specified, then targetVertexType must also be specified. If targetVertexType is specified, then edgeType must also be specified.

Parameters:

  • sourceVertexType: The name of the source vertex type.

  • sourceVertexId: The primary ID value of the source vertex instance.

  • edgeType: The name of the edge type.

  • targetVertexType: The name of the target vertex type.

  • targetVertexId: The primary ID value of the target vertex instance.

  • where: Comma separated list of conditions that are all applied on each edge’s attributes. The conditions are in logical conjunction (they are connected as if with an AND statement).

  • limit: Maximum number of edge instances to be returned after sorting.

  • sort: Comma-separated list of attributes the results should be sorted by.

  • timeout: Time allowed for successful execution. The default is 0, or no limit.

Returns:

A dictionary of edge_type: deleted_edge_count pairs.

Endpoint:

  • DELETE /graph/{graph_name}/edges/{source_vertex_type}/{source_vertex_id}/{edge_type}/{target_vertex_type}/{target_vertex_id}
    See the documentation for more details.

edgeSetToDataFrame()

edgeSetToDataFrame(edgeSet: list, withId: bool = True, withType: bool = False) → pd.DataFrame

Converts an edge set to Pandas DataFrame

Edge sets contain instances of the same edge type. Edge sets are not generated "naturally" like vertex sets. Instead, you need to collect edges in (global) accumulators, like when you want to visualize them in GraphStudio or by other tools.

For example:

SetAccum<EDGE> @@edges;

start = {country.*};

result =
    SELECT trg
    FROM   start:src -(city_in_country:e)- city:trg
    ACCUM  @@edges += e;

PRINT start, result, @@edges;

The @@edges is an edge set. It contains, for each edge instance, the source and target vertex type and ID, the edge type, a directedness indicator and the (optional) attributes.

start and result are vertex sets.

An edge set has this structure (when serialised as JSON):

[
{
"e_type": <edge_type_name>,
"from_type": <source_vertex_type_name>,
"from_id": <source_vertex_id>,
"to_type": <target_vertex_type_name>,
"to_id": <targe_vertex_id>,
"directed": <true_or_false>,
"attributes":
{
"attr1": <value1>,
"attr2": <value2>,
⋮
}
},
⋮
]

Parameters:

  • edgeSet: A JSON array containing an edge set in the format returned by queries (see below).

  • withId: Whether to include the type and primary ID of source and target vertices as a column. Default is True.

  • withType: Whether to include edge type info as a column. Default is False.

Returns:

A pandas DataFrame containing the edge attributes and optionally the type and primary ID or source and target vertices, and the edge type.