# -*- coding: utf-8 -*-
from ..utils import expand_by_edge_filter
from ...operations import subgraph
from ...pipeline import transformation
__all__ = [
'get_subgraph_by_edge_filter',
'get_subgraph_by_induction',
]
@transformation
def get_subgraph_by_edge_filter(graph, edge_predicates=None):
"""Induce a sub-graph on all edges that pass the given filters.
:param pybel.BELGraph graph: A BEL graph
:param edge_predicates: An edge predicate or list of edge predicates
:type edge_predicates: None or ((pybel.BELGraph, tuple, tuple, int) -> bool) or iter[(pybel.BELGraph, tuple, tuple, int) -> bool]
:return: A BEL sub-graph induced over the edges passing the given filters
:rtype: pybel.BELGraph
"""
rv = graph.fresh_copy()
expand_by_edge_filter(graph, rv, edge_predicates=edge_predicates)
return rv
[docs]@transformation
def get_subgraph_by_induction(graph, nodes):
"""Induce a sub-graph over the given nodes or return None if none of the nodes are in the given graph.
:param pybel.BELGraph graph: A BEL graph
:param iter[tuple] nodes: A list of BEL nodes in the graph
:rtype: Optional[pybel.BELGraph]
"""
if all(node not in graph for node in nodes):
return
return subgraph(graph, nodes)