xgt.EdgeFrame

class xgt.EdgeFrame(conn, name, schema, source, target, source_key, target_key, error_frame_name)

EdgeFrame object represents a collection of edges held on the xGT server; it can be used to retrieve information about them and should not be instantiated directly by the user. Methods that return this object: Connection.get_edge_frame(), Connection.get_edge_frames() and Connection.create_edge_frame(). Each edge in an EdgeFrame shares the same properties, described in EdgeFrame.schema.

The source vertex of each edge in an EdgeFrame must belong to the same VertexFrame. This name of this VertexFrame is given by EdgeFrame.source_name. The targe vertex of each edge in an EdgeFrame must belong to the same VertexFrame. This name of this VertexFrame is given by EdgeFrame.target_name.

For each edge in the EdgeFrame, its source vertex is identified by the edge property name given by EdgeFrame.source_key, which is be one of the properties listed in the schema. The edge target vertex is identified by the property name given by EdgeFrame.target_key.

Parameters

  • conn (Connection) – An open connection to an xGT server.

  • name (str) – Name of edge frame.

  • schema (list of pairs) – List of pairs associating property names with xGT data types. Each edge in the EdgeFrame will have these properties.

  • source (str or VertexFrame) – The name of a VertexFrame or a VertexFrame object. The source vertex of each edge in this EdgeFrame will belong to this VertexFrame.

  • target (str or VertexFrame) – The name of a VertexFrame or a VertexFrame object. The target vertex of each edge in this EdgeFrame will belong to this VertexFrame.

  • source_key (str) – The edge property name that identifies the source vertex of an edge. This is one of the properties from the schema.

  • target_key (str) – The edge property name that identifies the target vertex of an edge. This is one of the properties from the schema.

  • error_frame_name (str) – Name of the frame created to store errors encountered while loading data. (internal)

Examples

>>> import xgt
>>> conn = xgt.Connection()
>>> e1 = conn.create_edge_frame(
...        name = 'WorksFor',
...        schema = [['srcid', xgt.INT],
...                  ['role', xgt.TEXT],
...                  ['trgid', xgt.INT]],
...        source = 'People',
...        target = 'Companies',
...        source_key = 'srcid',
...        target_key = 'trgid')
>>> e2 = conn.get_edge_frame('RelatedTo') # An existing edge frame
>>> print(e1.name, e2.name)
__init__(conn, name, schema, source, target, source_key, target_key, error_frame_name)

Initialize self. See help(type(self)) for accurate signature.

Methods

__init__(conn, name, schema, source, target, …)

Initialize self.

get_data([offset, length])

Returns frame data starting at a given offset and spanning a given length.

get_data_pandas([offset, length])

Returns a Pandas DataFrame containing frame data starting at a given offset and spanning a given length.

insert(data)

Inserts data rows.

load(paths[, headerMode])

Loads data from one or more CSV files specified in the list of paths.

reset_visited_edges()

Resets the visited edges count for the frame.

save(path[, offset, length, headers])

Writes the rows from the frame to a CSV file in the path and the computer indicated by the path.

Attributes

error_frame_name

Name of the error table this frame will produce on errors.

name

Name of the table.

num_edges

Gets the number of edges in the edge frame.

num_rows

Gets the number of edges in the edge frame.

schema

Gets the property names and types of the table.

source_key

The edge property name that identifies the source vertex of an edge.

source_name

Gets the name of the source vertex frame.

target_key

The edge property name that identifies the target vertex of an edge.

target_name

Gets the name of the target vertex frame.

visited_edges

Gets the number of edges visited in this edge frame since the last
property error_frame_name

Name of the error table this frame will produce on errors.

Type

str

get_data(offset=0, length=None)

Returns frame data starting at a given offset and spanning a given length.

Parameters

  • offset (int) – Position (index) of the first row to be retrieved. Optional. Default=0.

  • length (int) – Maximum number of rows to be retrieved starting from the row indicated by offset. A value of ‘None’ means ‘all rows’ on and after the offset. Optional. Default=None.

Returns

Return type

list of lists

get_data_pandas(offset=0, length=None)

Returns a Pandas DataFrame containing frame data starting at a given offset and spanning a given length.

Parameters

  • offset (int) – Position (index) of the first row to be retrieved. Optional. Default=0.

  • length (int) – Maximum number of rows to be retrieved starting from the row indicated by offset. A value of ‘None’ means ‘all rows’ on and after the offset. Optional. Default=None.

Returns

Return type

Pandas DataFrame

insert(data)

Inserts data rows. The properties of the new data must match the schema in both order and type.

Parameters

data (list or Pandas dataframe) – Data represented by a list of lists of data items or by a Pandas Dataframe.

load(paths, headerMode='none')

Loads data from one or more CSV files specified in the list of paths. Each path may have its own protocol as described below.

Parameters

  • paths (list) –

    Paths to the CSV files.

    Syntax for one CSV file path

    Resource type

    Path syntax

    local to python:

    ’<path to csv file>’ ‘xgt://<path to csv file>’

    xgtd computer:

    ’xgtd://<path to csv file>’

    AWS s3:

    ’s3://<path to csv file>’

    https site:

    ’https://<path to csv file>’

    http site:

    ’http://<path to csv file>’

    ftps server:

    ’ftps://<path to csv file>’

    ftp server:

    ’ftp://<path to csv file>’

  • headerMode (str) –

    Indicates if the files contain headers:

    • HeaderMode.NONE

    • HeaderMode.IGNORE

    • HeaderMode.NORMAL

    • HeaderMode.STRICT

    Optional. Default=HeaderMode.NONE.

property name

Name of the table.

Type

str

property num_edges

Gets the number of edges in the edge frame.

Type

int

property num_rows

Gets the number of edges in the edge frame.

Type

int

reset_visited_edges()

Resets the visited edges count for the frame.

save(path, offset=0, length=None, headers=False)

Writes the rows from the frame to a CSV file in the path and the computer indicated by the path.

Parameters

  • path (str) –

    Path to the CSV file.

    Syntax for one CSV file path

    Resource type

    Path syntax

    local to python:

    ’<path to csv file>’ ‘xgt://<path to csv file>’

    xgtd computer:

    ’xgtd://<path to csv file>’

  • offset (int) – Position (index) of the first row to be retrieved. Optional. Default=0.

  • length (int) – Maximum number of rows to be retrieved. Optional. Default=None.

  • headers (boolean) – Indicates if headers should be added. Optional. Default=False.

property schema

Gets the property names and types of the table.

Type

list of lists

property source_key

The edge property name that identifies the source vertex of an edge.

Type

str

property source_name

Gets the name of the source vertex frame.

Type

str

property target_key

The edge property name that identifies the target vertex of an edge.

Type

str

property target_name

Gets the name of the target vertex frame.

Type

str

property visited_edges
Gets the number of edges visited in this edge frame since the last

reset.

The count only includes jobs that were started when the configuration variable stats.frame_stats is set to true.

Type

int