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graph.rs
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graph.rs
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// Licensed under the Apache License, Version 2.0 (the "License"); you may
// not use this file except in compliance with the License. You may obtain
// a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations
// under the License.
use std::cmp;
use std::collections::BTreeMap;
use std::fs::File;
use std::io::prelude::*;
use std::io::{BufReader, BufWriter};
use std::ops::{Index, IndexMut};
use std::str;
use hashbrown::{HashMap, HashSet};
use pyo3::class::PyMappingProtocol;
use pyo3::exceptions::PyIndexError;
use pyo3::gc::{PyGCProtocol, PyVisit};
use pyo3::prelude::*;
use pyo3::types::{PyBool, PyDict, PyList, PyLong, PyString, PyTuple};
use pyo3::PyTraverseError;
use pyo3::Python;
use ndarray::prelude::*;
use numpy::PyReadonlyArray2;
use super::dot_utils::build_dot;
use super::iterators::{
EdgeIndexMap, EdgeIndices, EdgeList, NodeIndices, WeightedEdgeList,
};
use super::{find_node_by_weight, NoEdgeBetweenNodes, NodesRemoved};
use petgraph::algo;
use petgraph::graph::{EdgeIndex, NodeIndex};
use petgraph::prelude::*;
use petgraph::stable_graph::StableDiGraph;
use petgraph::stable_graph::StableUnGraph;
use petgraph::visit::{
GetAdjacencyMatrix, GraphBase, GraphProp, IntoEdgeReferences, IntoEdges,
IntoNeighbors, IntoNeighborsDirected, IntoNodeIdentifiers,
IntoNodeReferences, NodeCompactIndexable, NodeCount, NodeFiltered,
NodeIndexable, Visitable,
};
/// A class for creating undirected graphs
///
/// The PyGraph class is used to create an undirected graph. It can be a
/// multigraph (have multiple edges between nodes). Each node and edge
/// (although rarely used for edges) is indexed by an integer id. These ids
/// are stable for the lifetime of the graph object and on node or edge
/// deletions you can have holes in the list of indices for the graph.
/// Node indices will be reused on additions after removal. For example:
///
/// .. jupyter-execute::
///
/// import retworkx
///
/// graph = retworkx.PyGraph()
/// graph.add_nodes_from(list(range(5)))
/// graph.add_nodes_from(list(range(2)))
/// graph.remove_node(2)
/// print("After deletion:", graph.node_indexes())
/// res_manual = graph.add_node(None)
/// print("After adding a new node:", graph.node_indexes())
///
/// Additionally, each node and edge contains an arbitrary Python object as a
/// weight/data payload. You can use the index for access to the data payload
/// as in the following example:
///
/// .. jupyter-execute::
///
/// import retworkx
///
/// graph = retworkx.PyGraph()
/// data_payload = "An arbitrary Python object"
/// node_index = graph.add_node(data_payload)
/// print("Node Index: %s" % node_index)
/// print(graph[node_index])
///
/// The PyDiGraph implements the Python mapping protocol for nodes so in
/// addition to access you can also update the data payload with:
///
/// .. jupyter-execute::
///
/// import retworkx
///
/// graph = retworkx.PyGraph()
/// data_payload = "An arbitrary Python object"
/// node_index = graph.add_node(data_payload)
/// graph[node_index] = "New Payload"
/// print("Node Index: %s" % node_index)
/// print(graph[node_index])
///
/// By default a ``PyGraph`` is a multigraph (meaning there can be parallel
/// edges between nodes) however this can be disabled by setting the
/// ``multigraph`` kwarg to ``False`` when calling the ``PyGraph``
/// constructor. For example::
///
/// import retworkx
/// graph = retworkx.PyGraph(multigraph=False)
///
/// This can only be set at ``PyGraph`` initialization and not adjusted after
/// creation. When :attr:`~retworkx.PyGraph.multigraph` is set to ``False``
/// if a method call is made that would add a parallel edge it will instead
/// update the existing edge's weight/data payload.
///
/// :param bool multigraph: When this is set to ``False`` the created PyGraph
/// object will not be a multigraph. When ``False`` if a method call is
/// made that would add parallel edges the the weight/weight from that
/// method call will be used to update the existing edge in place.
#[pyclass(module = "retworkx", subclass, gc)]
#[pyo3(text_signature = "(/, multigraph=True)")]
#[derive(Clone)]
pub struct PyGraph {
pub graph: StableUnGraph<PyObject, PyObject>,
pub node_removed: bool,
pub multigraph: bool,
}
pub type Edges<'a, E> =
petgraph::stable_graph::Edges<'a, E, petgraph::Undirected>;
impl GraphBase for PyGraph {
type NodeId = NodeIndex;
type EdgeId = EdgeIndex;
}
impl<'a> NodesRemoved for &'a PyGraph {
fn nodes_removed(&self) -> bool {
self.node_removed
}
}
impl NodeCount for PyGraph {
fn node_count(&self) -> usize {
self.graph.node_count()
}
}
impl GraphProp for PyGraph {
type EdgeType = petgraph::Undirected;
fn is_directed(&self) -> bool {
false
}
}
impl petgraph::visit::Visitable for PyGraph {
type Map = <StableUnGraph<PyObject, PyObject> as Visitable>::Map;
fn visit_map(&self) -> Self::Map {
self.graph.visit_map()
}
fn reset_map(&self, map: &mut Self::Map) {
self.graph.reset_map(map)
}
}
impl petgraph::visit::Data for PyGraph {
type NodeWeight = PyObject;
type EdgeWeight = PyObject;
}
impl petgraph::data::DataMap for PyGraph {
fn node_weight(&self, id: Self::NodeId) -> Option<&Self::NodeWeight> {
self.graph.node_weight(id)
}
fn edge_weight(&self, id: Self::EdgeId) -> Option<&Self::EdgeWeight> {
self.graph.edge_weight(id)
}
}
impl petgraph::data::DataMapMut for PyGraph {
fn node_weight_mut(
&mut self,
id: Self::NodeId,
) -> Option<&mut Self::NodeWeight> {
self.graph.node_weight_mut(id)
}
fn edge_weight_mut(
&mut self,
id: Self::EdgeId,
) -> Option<&mut Self::EdgeWeight> {
self.graph.edge_weight_mut(id)
}
}
impl<'a> IntoNeighbors for &'a PyGraph {
type Neighbors = petgraph::stable_graph::Neighbors<'a, PyObject>;
fn neighbors(self, n: NodeIndex) -> Self::Neighbors {
self.graph.neighbors(n)
}
}
impl<'a> IntoNeighborsDirected for &'a PyGraph {
type NeighborsDirected = petgraph::stable_graph::Neighbors<'a, PyObject>;
fn neighbors_directed(
self,
n: NodeIndex,
d: petgraph::Direction,
) -> Self::Neighbors {
self.graph.neighbors_directed(n, d)
}
}
impl<'a> IntoEdgeReferences for &'a PyGraph {
type EdgeRef = petgraph::stable_graph::EdgeReference<'a, PyObject>;
type EdgeReferences = petgraph::stable_graph::EdgeReferences<'a, PyObject>;
fn edge_references(self) -> Self::EdgeReferences {
self.graph.edge_references()
}
}
impl<'a> IntoEdges for &'a PyGraph {
type Edges = Edges<'a, PyObject>;
fn edges(self, a: Self::NodeId) -> Self::Edges {
self.graph.edges(a)
}
}
impl<'a> IntoNodeIdentifiers for &'a PyGraph {
type NodeIdentifiers = petgraph::stable_graph::NodeIndices<'a, PyObject>;
fn node_identifiers(self) -> Self::NodeIdentifiers {
self.graph.node_identifiers()
}
}
impl<'a> IntoNodeReferences for &'a PyGraph {
type NodeRef = (NodeIndex, &'a PyObject);
type NodeReferences = petgraph::stable_graph::NodeReferences<'a, PyObject>;
fn node_references(self) -> Self::NodeReferences {
self.graph.node_references()
}
}
impl NodeIndexable for PyGraph {
fn node_bound(&self) -> usize {
self.graph.node_bound()
}
fn to_index(&self, ix: NodeIndex) -> usize {
self.graph.to_index(ix)
}
fn from_index(&self, ix: usize) -> Self::NodeId {
self.graph.from_index(ix)
}
}
impl NodeCompactIndexable for PyGraph {}
impl Index<NodeIndex> for PyGraph {
type Output = PyObject;
fn index(&self, index: NodeIndex) -> &PyObject {
&self.graph[index]
}
}
impl IndexMut<NodeIndex> for PyGraph {
fn index_mut(&mut self, index: NodeIndex) -> &mut PyObject {
&mut self.graph[index]
}
}
impl Index<EdgeIndex> for PyGraph {
type Output = PyObject;
fn index(&self, index: EdgeIndex) -> &PyObject {
&self.graph[index]
}
}
impl IndexMut<EdgeIndex> for PyGraph {
fn index_mut(&mut self, index: EdgeIndex) -> &mut PyObject {
&mut self.graph[index]
}
}
impl GetAdjacencyMatrix for PyGraph {
type AdjMatrix =
<StableUnGraph<PyObject, PyObject> as GetAdjacencyMatrix>::AdjMatrix;
fn adjacency_matrix(&self) -> Self::AdjMatrix {
self.graph.adjacency_matrix()
}
fn is_adjacent(
&self,
matrix: &Self::AdjMatrix,
a: NodeIndex,
b: NodeIndex,
) -> bool {
self.graph.is_adjacent(matrix, a, b)
}
}
#[pymethods]
impl PyGraph {
#[new]
#[args(multigraph = "true")]
fn new(multigraph: bool) -> Self {
PyGraph {
graph: StableUnGraph::<PyObject, PyObject>::default(),
node_removed: false,
multigraph,
}
}
fn __getstate__(&self, py: Python) -> PyResult<PyObject> {
let out_dict = PyDict::new(py);
let node_dict = PyDict::new(py);
let mut out_list: Vec<PyObject> =
Vec::with_capacity(self.graph.edge_count());
out_dict.set_item("nodes", node_dict)?;
out_dict.set_item("nodes_removed", self.node_removed)?;
out_dict.set_item("multigraph", self.multigraph)?;
for node_index in self.graph.node_indices() {
let node_data = self.graph.node_weight(node_index).unwrap();
node_dict.set_item(node_index.index(), node_data)?;
}
for edge in self.graph.edge_indices() {
let edge_w = self.graph.edge_weight(edge);
let endpoints = self.graph.edge_endpoints(edge).unwrap();
let triplet = (endpoints.0.index(), endpoints.1.index(), edge_w)
.to_object(py);
out_list.push(triplet);
}
let py_out_list: PyObject = PyList::new(py, out_list).into();
out_dict.set_item("edges", py_out_list)?;
Ok(out_dict.into())
}
fn __setstate__(&mut self, py: Python, state: PyObject) -> PyResult<()> {
self.graph = StableUnGraph::<PyObject, PyObject>::default();
let dict_state = state.cast_as::<PyDict>(py)?;
let nodes_dict =
dict_state.get_item("nodes").unwrap().downcast::<PyDict>()?;
let edges_list =
dict_state.get_item("edges").unwrap().downcast::<PyList>()?;
let nodes_removed_raw = dict_state
.get_item("nodes_removed")
.unwrap()
.downcast::<PyBool>()?;
self.node_removed = nodes_removed_raw.extract()?;
let multigraph_raw = dict_state
.get_item("multigraph")
.unwrap()
.downcast::<PyBool>()?;
self.multigraph = multigraph_raw.extract()?;
let mut node_indices: Vec<usize> = Vec::new();
for raw_index in nodes_dict.keys() {
let tmp_index = raw_index.downcast::<PyLong>()?;
node_indices.push(tmp_index.extract()?);
}
if node_indices.is_empty() {
return Ok(());
}
let max_index: usize = *node_indices.iter().max().unwrap();
let mut tmp_nodes: Vec<NodeIndex> = Vec::new();
let mut node_count: usize = 0;
while max_index >= self.graph.node_bound() {
match nodes_dict.get_item(node_count) {
Some(raw_data) => {
self.graph.add_node(raw_data.into());
}
None => {
let tmp_node = self.graph.add_node(py.None());
tmp_nodes.push(tmp_node);
}
};
node_count += 1;
}
for tmp_node in tmp_nodes {
self.graph.remove_node(tmp_node);
}
for raw_edge in edges_list.iter() {
let edge = raw_edge.downcast::<PyTuple>()?;
let raw_p_index = edge.get_item(0).downcast::<PyLong>()?;
let parent: usize = raw_p_index.extract()?;
let p_index = NodeIndex::new(parent);
let raw_c_index = edge.get_item(1).downcast::<PyLong>()?;
let child: usize = raw_c_index.extract()?;
let c_index = NodeIndex::new(child);
let edge_data = edge.get_item(2);
self.graph.add_edge(p_index, c_index, edge_data.into());
}
Ok(())
}
/// Whether the graph is a multigraph (allows multiple edges between
/// nodes) or not
///
/// If set to ``False`` multiple edges between nodes are not allowed and
/// calls that would add a parallel edge will instead update the existing
/// edge
#[getter]
fn multigraph(&self) -> bool {
self.multigraph
}
/// Detect if the graph has parallel edges or not
///
/// :returns: ``True`` if the graph has parallel edges, otherwise ``False``
/// :rtype: bool
#[pyo3(text_signature = "(self)")]
fn has_parallel_edges(&self) -> bool {
if !self.multigraph {
return false;
}
let mut edges: HashSet<[NodeIndex; 2]> =
HashSet::with_capacity(2 * self.graph.edge_count());
for edge in self.graph.edge_references() {
let endpoints = [edge.source(), edge.target()];
let endpoints_rev = [edge.target(), edge.source()];
if edges.contains(&endpoints) || edges.contains(&endpoints_rev) {
return true;
}
edges.insert(endpoints);
edges.insert(endpoints_rev);
}
false
}
/// Return the number of nodes in the graph
#[pyo3(text_signature = "(self)")]
pub fn num_nodes(&self) -> usize {
self.graph.node_count()
}
/// Return the number of edges in the graph
#[pyo3(text_signature = "(self)")]
pub fn num_edges(&self) -> usize {
self.graph.edge_count()
}
/// Return a list of all edge data.
///
/// :returns: A list of all the edge data objects in the graph
/// :rtype: list
#[pyo3(text_signature = "(self)")]
pub fn edges(&self) -> Vec<&PyObject> {
self.graph
.edge_indices()
.map(|edge| self.graph.edge_weight(edge).unwrap())
.collect()
}
/// Return a list of all edge indices.
///
/// :returns: A list of all the edge indices in the graph
/// :rtype: EdgeIndices
#[pyo3(text_signature = "(self)")]
pub fn edge_indices(&self) -> EdgeIndices {
EdgeIndices {
edges: self.graph.edge_indices().map(|edge| edge.index()).collect(),
}
}
/// Return a list of all node data.
///
/// :returns: A list of all the node data objects in the graph
/// :rtype: list
#[pyo3(text_signature = "(self)")]
pub fn nodes(&self) -> Vec<&PyObject> {
self.graph
.node_indices()
.map(|node| self.graph.node_weight(node).unwrap())
.collect()
}
/// Return a list of all node indexes.
///
/// :returns: A list of all the node indexes in the graph
/// :rtype: NodeIndices
#[pyo3(text_signature = "(self)")]
pub fn node_indexes(&self) -> NodeIndices {
NodeIndices {
nodes: self.graph.node_indices().map(|node| node.index()).collect(),
}
}
/// Return True if there is an edge between node_a to node_b.
///
/// :param int node_a: The node index to check for an edge between
/// :param int node_b: The node index to check for an edge between
///
/// :returns: True if there is an edge false if there is no edge
/// :rtype: bool
#[pyo3(text_signature = "(self, node_a, node_b, /)")]
pub fn has_edge(&self, node_a: usize, node_b: usize) -> bool {
let index_a = NodeIndex::new(node_a);
let index_b = NodeIndex::new(node_b);
self.graph.find_edge(index_a, index_b).is_some()
}
/// Return the edge data for the edge between 2 nodes.
///
/// Note if there are multiple edges between the nodes only one will be
/// returned. To get all edge data objects use
/// :meth:`~retworkx.PyGraph.get_all_edge_data`
///
/// :param int node_a: The index for the first node
/// :param int node_b: The index for the second node
///
/// :returns: The data object set for the edge
/// :raises NoEdgeBetweenNodes: when there is no edge between the provided
/// nodes
#[pyo3(text_signature = "(self, node_a, node_b, /)")]
pub fn get_edge_data(
&self,
node_a: usize,
node_b: usize,
) -> PyResult<&PyObject> {
let index_a = NodeIndex::new(node_a);
let index_b = NodeIndex::new(node_b);
let edge_index = match self.graph.find_edge(index_a, index_b) {
Some(edge_index) => edge_index,
None => {
return Err(NoEdgeBetweenNodes::new_err(
"No edge found between nodes",
))
}
};
let data = self.graph.edge_weight(edge_index).unwrap();
Ok(data)
}
/// Update an edge's weight/payload in place
///
/// If there are parallel edges in the graph only one edge will be updated.
/// if you need to update a specific edge or need to ensure all parallel
/// edges get updated you should use
/// :meth:`~retworkx.PyGraph.update_edge_by_index` instead.
///
/// :param int source: The index for the first node
/// :param int target: The index for the second node
///
/// :raises NoEdgeBetweenNodes: When there is no edge between nodes
#[pyo3(text_signature = "(self, source, target, edge /)")]
pub fn update_edge(
&mut self,
source: usize,
target: usize,
edge: PyObject,
) -> PyResult<()> {
let index_a = NodeIndex::new(source);
let index_b = NodeIndex::new(target);
let edge_index = match self.graph.find_edge(index_a, index_b) {
Some(edge_index) => edge_index,
None => {
return Err(NoEdgeBetweenNodes::new_err(
"No edge found between nodes",
))
}
};
let data = self.graph.edge_weight_mut(edge_index).unwrap();
*data = edge;
Ok(())
}
/// Update an edge's weight/data payload in place by the edge index
///
/// :param int edge_index: The index for the edge
/// :param object edge: The data payload/weight to update the edge with
///
/// :raises NoEdgeBetweenNodes: When there is no edge between nodes
#[pyo3(text_signature = "(self, source, target, edge /)")]
pub fn update_edge_by_index(
&mut self,
edge_index: usize,
edge: PyObject,
) -> PyResult<()> {
match self.graph.edge_weight_mut(EdgeIndex::new(edge_index)) {
Some(data) => *data = edge,
None => {
return Err(PyIndexError::new_err("No edge found for index"))
}
};
Ok(())
}
/// Return the node data for a given node index
///
/// :param int node: The index for the node
///
/// :returns: The data object set for that node
/// :raises IndexError: when an invalid node index is provided
#[pyo3(text_signature = "(self, node, /)")]
pub fn get_node_data(&self, node: usize) -> PyResult<&PyObject> {
let index = NodeIndex::new(node);
let node = match self.graph.node_weight(index) {
Some(node) => node,
None => {
return Err(PyIndexError::new_err("No node found for index"))
}
};
Ok(node)
}
/// Return the edge data for all the edges between 2 nodes.
///
/// :param int node_a: The index for the first node
/// :param int node_b: The index for the second node
///
/// :returns: A list with all the data objects for the edges between nodes
/// :rtype: list
/// :raises NoEdgeBetweenNodes: When there is no edge between nodes
#[pyo3(text_signature = "(self, node_a, node_b, /)")]
pub fn get_all_edge_data(
&self,
node_a: usize,
node_b: usize,
) -> PyResult<Vec<&PyObject>> {
let index_a = NodeIndex::new(node_a);
let index_b = NodeIndex::new(node_b);
let out: Vec<&PyObject> = self
.graph
.edges(index_a)
.filter(|edge| edge.target() == index_b)
.map(|edge| edge.weight())
.collect();
if out.is_empty() {
Err(NoEdgeBetweenNodes::new_err("No edge found between nodes"))
} else {
Ok(out)
}
}
/// Get edge list
///
/// Returns a list of tuples of the form ``(source, target)`` where
/// ``source`` and ``target`` are the node indices.
///
/// :returns: An edge list with weights
/// :rtype: EdgeList
#[pyo3(text_signature = "(self)")]
pub fn edge_list(&self) -> EdgeList {
EdgeList {
edges: self
.edge_references()
.map(|edge| (edge.source().index(), edge.target().index()))
.collect(),
}
}
/// Get edge list with weights
///
/// Returns a list of tuples of the form ``(source, target, weight)`` where
/// ``source`` and ``target`` are the node indices and ``weight`` is the
/// payload of the edge.
///
/// :returns: An edge list with weights
/// :rtype: WeightedEdgeList
#[pyo3(text_signature = "(self)")]
pub fn weighted_edge_list(&self, py: Python) -> WeightedEdgeList {
WeightedEdgeList {
edges: self
.edge_references()
.map(|edge| {
(
edge.source().index(),
edge.target().index(),
edge.weight().clone_ref(py),
)
})
.collect(),
}
}
/// Get an edge index map
///
/// Returns a read only mapping from edge indices to the weighted edge
/// tuple. The return is a mapping of the form:
/// ``{0: (0, 1, "weight"), 1: (2, 3, 2.3)}``
///
/// :returns: An edge index map
/// :rtype: EdgeIndexMap
#[pyo3(text_signature = "(self)")]
pub fn edge_index_map(&self, py: Python) -> EdgeIndexMap {
EdgeIndexMap {
edge_map: self
.edge_references()
.map(|edge| {
(
edge.id().index(),
(
edge.source().index(),
edge.target().index(),
edge.weight().clone_ref(py),
),
)
})
.collect(),
}
}
/// Remove a node from the graph.
///
/// :param int node: The index of the node to remove. If the index is not
/// present in the graph it will be ignored and this function will
/// have no effect.
#[pyo3(text_signature = "(self, node, /)")]
pub fn remove_node(&mut self, node: usize) -> PyResult<()> {
let index = NodeIndex::new(node);
self.graph.remove_node(index);
self.node_removed = true;
Ok(())
}
/// Add an edge between 2 nodes.
///
/// If :attr:`~retworkx.PyGraph.multigraph` is ``False`` and an edge already
/// exists between ``node_a`` and ``node_b`` the weight/payload of that
/// existing edge will be updated to be ``edge``.
///
/// :param int node_a: Index of the parent node
/// :param int node_b: Index of the child node
/// :param edge: The object to set as the data for the edge. It can be any
/// python object.
///
/// :returns: The edge index for the newly created (or updated in the case
/// of an existing edge with ``multigraph=False``) edge.
/// :rtype: int
#[pyo3(text_signature = "(self, node_a, node_b, edge, /)")]
pub fn add_edge(
&mut self,
node_a: usize,
node_b: usize,
edge: PyObject,
) -> PyResult<usize> {
let p_index = NodeIndex::new(node_a);
let c_index = NodeIndex::new(node_b);
if !self.multigraph {
let exists = self.graph.find_edge(p_index, c_index);
if let Some(index) = exists {
let edge_weight = self.graph.edge_weight_mut(index).unwrap();
*edge_weight = edge;
return Ok(index.index());
}
}
let edge = self.graph.add_edge(p_index, c_index, edge);
Ok(edge.index())
}
/// Add new edges to the graph.
///
/// :param list obj_list: A list of tuples of the form
/// ``(node_a, node_b, obj)`` to attach to the graph. ``node_a`` and
/// ``node_b`` are integer indexes describing where an edge should be
/// added, and ``obj`` is the python object for the edge data.
///
/// If :attr:`~retworkx.PyGraph.multigraph` is ``False`` and an edge already
/// exists between ``node_a`` and ``node_b`` the weight/payload of that
/// existing edge will be updated to be ``edge``. This will occur in order
/// from ``obj_list`` so if there are multiple parallel edges in ``obj_list``
/// the last entry will be used.
///
/// :returns: A list of int indices of the newly created edges
/// :rtype: list
#[pyo3(text_signature = "(self, obj_list, /)")]
pub fn add_edges_from(
&mut self,
obj_list: Vec<(usize, usize, PyObject)>,
) -> PyResult<Vec<usize>> {
let mut out_list: Vec<usize> = Vec::with_capacity(obj_list.len());
for obj in obj_list {
let p_index = NodeIndex::new(obj.0);
let c_index = NodeIndex::new(obj.1);
if !self.multigraph {
let exists = self.graph.find_edge(p_index, c_index);
if let Some(index) = exists {
let edge_weight =
self.graph.edge_weight_mut(index).unwrap();
*edge_weight = obj.2;
out_list.push(index.index());
continue;
}
}
let edge = self.graph.add_edge(p_index, c_index, obj.2);
out_list.push(edge.index());
}
Ok(out_list)
}
/// Add new edges to the graph without python data.
///
/// :param list obj_list: A list of tuples of the form
/// ``(parent, child)`` to attach to the graph. ``parent`` and
/// ``child`` are integer indexes describing where an edge should be
/// added. Unlike :meth:`add_edges_from` there is no data payload and
/// when the edge is created None will be used.
///
/// If :attr:`~retworkx.PyGraph.multigraph` is ``False`` and an edge already
/// exists between ``node_a`` and ``node_b`` the weight/payload of that
/// existing edge will be updated to be ``None``.
///
/// :returns: A list of int indices of the newly created edges
/// :rtype: list
#[pyo3(text_signature = "(self, obj_list, /)")]
pub fn add_edges_from_no_data(
&mut self,
py: Python,
obj_list: Vec<(usize, usize)>,
) -> PyResult<Vec<usize>> {
let mut out_list: Vec<usize> = Vec::with_capacity(obj_list.len());
for obj in obj_list {
let p_index = NodeIndex::new(obj.0);
let c_index = NodeIndex::new(obj.1);
if !self.multigraph {
let exists = self.graph.find_edge(p_index, c_index);
if let Some(index) = exists {
let edge_weight =
self.graph.edge_weight_mut(index).unwrap();
*edge_weight = py.None();
out_list.push(index.index());
continue;
}
}
let edge = self.graph.add_edge(p_index, c_index, py.None());
out_list.push(edge.index());
}
Ok(out_list)
}
/// Extend graph from an edge list
///
/// This method differs from :meth:`add_edges_from_no_data` in that it will
/// add nodes if a node index is not present in the edge list.
///
/// If :attr:`~retworkx.PyGraph.multigraph` is ``False`` and an edge already
/// exists between ``node_a`` and ``node_b`` the weight/payload of that
/// existing edge will be updated to be ``None``.
///
/// :param list edge_list: A list of tuples of the form ``(source, target)``
/// where source and target are integer node indices. If the node index
/// is not present in the graph, nodes will be added (with a node
/// weight of ``None``) to that index.
#[pyo3(text_signature = "(self, edge_list, /)")]
pub fn extend_from_edge_list(
&mut self,
py: Python,
edge_list: Vec<(usize, usize)>,
) {
for (source, target) in edge_list {
let max_index = cmp::max(source, target);
while max_index >= self.node_count() {
self.graph.add_node(py.None());
}
let source_index = NodeIndex::new(source);
let target_index = NodeIndex::new(target);
if !self.multigraph {
let exists = self.graph.find_edge(source_index, target_index);
if let Some(index) = exists {
let edge_weight =
self.graph.edge_weight_mut(index).unwrap();
*edge_weight = py.None();
continue;
}
}
self.graph.add_edge(source_index, target_index, py.None());
}
}
/// Extend graph from a weighted edge list
///
/// This method differs from :meth:`add_edges_from` in that it will
/// add nodes if a node index is not present in the edge list.
///
/// If :attr:`~retworkx.PyGraph.multigraph` is ``False`` and an edge already
/// exists between ``node_a`` and ``node_b`` the weight/payload of that
/// existing edge will be updated to be ``edge``. This will occur in order
/// from ``obj_list`` so if there are multiple parallel edges in ``obj_list``
/// the last entry will be used.
///
/// :param list edge_list: A list of tuples of the form
/// ``(source, target, weight)`` where source and target are integer
/// node indices. If the node index is not present in the graph,
/// nodes will be added (with a node weight of ``None``) to that index.
#[pyo3(text_signature = "(self, edge_lsit, /)")]
pub fn extend_from_weighted_edge_list(
&mut self,
py: Python,
edge_list: Vec<(usize, usize, PyObject)>,
) {
for (source, target, weight) in edge_list {
let max_index = cmp::max(source, target);
while max_index >= self.node_count() {
self.graph.add_node(py.None());
}
let source_index = NodeIndex::new(source);
let target_index = NodeIndex::new(target);
if !self.multigraph {
let exists = self.graph.find_edge(source_index, target_index);
if let Some(index) = exists {
let edge_weight =
self.graph.edge_weight_mut(index).unwrap();
*edge_weight = weight;
continue;
}
}
self.graph.add_edge(source_index, target_index, weight);
}
}
/// Remove an edge between 2 nodes.
///
/// Note if there are multiple edges between the specified nodes only one
/// will be removed.
///
/// :param int parent: The index for the parent node.
/// :param int child: The index of the child node.
///
/// :raises NoEdgeBetweenNodes: If there are no edges between the nodes
/// specified
#[pyo3(text_signature = "(self, node_a, node_b, /)")]
pub fn remove_edge(
&mut self,
node_a: usize,
node_b: usize,
) -> PyResult<()> {
let p_index = NodeIndex::new(node_a);
let c_index = NodeIndex::new(node_b);
let edge_index = match self.graph.find_edge(p_index, c_index) {
Some(edge_index) => edge_index,
None => {
return Err(NoEdgeBetweenNodes::new_err(
"No edge found between nodes",
))
}
};
self.graph.remove_edge(edge_index);
Ok(())
}
/// Remove an edge identified by the provided index
///
/// :param int edge: The index of the edge to remove
#[pyo3(text_signature = "(self, edge, /)")]
pub fn remove_edge_from_index(&mut self, edge: usize) -> PyResult<()> {
let edge_index = EdgeIndex::new(edge);
self.graph.remove_edge(edge_index);
Ok(())
}
/// Remove edges from the graph.
///
/// Note if there are multiple edges between the specified nodes only one
/// will be removed.
///
/// :param list index_list: A list of node index pairs to remove from
/// the graph
#[pyo3(text_signature = "(self, index_list, /)")]
pub fn remove_edges_from(
&mut self,
index_list: Vec<(usize, usize)>,
) -> PyResult<()> {
for (p_index, c_index) in index_list
.iter()
.map(|(x, y)| (NodeIndex::new(*x), NodeIndex::new(*y)))
{
let edge_index = match self.graph.find_edge(p_index, c_index) {
Some(edge_index) => edge_index,
None => {
return Err(NoEdgeBetweenNodes::new_err(
"No edge found between nodes",
))
}
};
self.graph.remove_edge(edge_index);
}
Ok(())
}
/// Add a new node to the graph.
///
/// :param obj: The python object to attach to the node
///
/// :returns: The index of the newly created node
/// :rtype: int
#[pyo3(text_signature = "(self, obj, /)")]
pub fn add_node(&mut self, obj: PyObject) -> PyResult<usize> {
let index = self.graph.add_node(obj);
Ok(index.index())
}
/// Add new nodes to the graph.
///
/// :param list obj_list: A list of python object to attach to the graph.
///
/// :returns indices: A list of int indices of the newly created nodes
/// :rtype: NodeIndices
#[pyo3(text_signature = "(self, obj_list, /)")]
pub fn add_nodes_from(&mut self, obj_list: Vec<PyObject>) -> NodeIndices {
let out_list: Vec<usize> = obj_list
.into_iter()
.map(|obj| self.graph.add_node(obj).index())