Added clear, clear_edges functions to PyGraph and PyDiGraph objects (#…

…993)

* First pass at testing infrastructure + graph.rs file changes

* Fixed clear, clear_edges for graph.rs and digraph.rs, added tests, added documentation

* fix for docstring for clear_edges in digraph

* docstring fix for graph.rs

* Minor fixes for codestyle for python lint

* Added new tests to show reuse after using clear, clear_edges, updated docs

* Adding fix for build error with prev commit

* fixes from black codestyle format

* fixed flake8 F841 - variable assigned to but never used errors

* retry at fix for F841 error, used noqa

* fixes for black

* fixes for CICD, F841 local variable unused error

* flake8 fixes

releasenotes/notes/add-clear-and-clear_edges-for-graphs-041b166aa541639c.yaml

@@ -0,0 +1,10 @@
+---
+features:
+  - |
+    Added a new function, :func:`clear` that clears all nodes and edges
+    from a :class:`rustworkx.PyGraph` or :class:`rustworkx.PyDiGraph` 
+
+  - |
+    Added a new function, :func:`clear_edges` that clears all edges for
+    :class:`rustworkx.PyGraph` or :class:`rustworkx.PyDiGraph` without
+    modifying nodes

src/digraph.rs

@@ -492,6 +492,20 @@ impl PyDiGraph {
         }
         false
     }
+
+    /// Clear all nodes and edges
+    #[pyo3(text_signature = "(self)")]
+    pub fn clear(&mut self) {
+        self.graph.clear();
+        self.node_removed = true;
+    }
+
+    /// Clears all edges, leaves nodes intact
+    #[pyo3(text_signature = "(self)")]
+    pub fn clear_edges(&mut self) {
+        self.graph.clear_edges();
+    }
+
     /// Return the number of nodes in the graph
     #[pyo3(text_signature = "(self)")]
     pub fn num_nodes(&self) -> usize {

src/graph.rs

@@ -368,6 +368,19 @@ impl PyGraph {
         false
     }
 
+    /// Clears all nodes and edges
+    #[pyo3(text_signature = "(self)")]
+    pub fn clear(&mut self) {
+        self.graph.clear();
+        self.node_removed = true;
+    }
+
+    /// Clears all edges, leaves nodes intact
+    #[pyo3(text_signature = "(self)")]
+    pub fn clear_edges(&mut self) {
+        self.graph.clear_edges();
+    }
+
     /// Return the number of nodes in the graph
     #[pyo3(text_signature = "(self)")]
     pub fn num_nodes(&self) -> usize {

tests/rustworkx_tests/digraph/test_clear.py

@@ -0,0 +1,66 @@
+# 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.
+
+import unittest
+
+import rustworkx
+
+
+class TestClear(unittest.TestCase):
+    def test_clear(self):
+        dag = rustworkx.PyDAG()
+        node_a = dag.add_node("a")
+        dag.add_child(node_a, "b", {"a": 1})
+        dag.add_child(node_a, "c", {"a": 2})
+        dag.clear()
+        self.assertEqual(dag.num_nodes(), 0)
+        self.assertEqual(dag.num_edges(), 0)
+        self.assertEqual(dag.nodes(), [])
+        self.assertEqual(dag.edges(), [])
+
+    def test_clear_reuse(self):
+        dag = rustworkx.PyDAG()
+        node_a = dag.add_node("a")
+        dag.add_child(node_a, "b", {"a": 1})
+        dag.add_child(node_a, "c", {"a": 2})
+        dag.clear()
+        node_a = dag.add_node("a")
+        dag.add_child(node_a, "b", {"a": 1})
+        dag.add_child(node_a, "c", {"a": 2})
+        self.assertEqual(dag.num_nodes(), 3)
+        self.assertEqual(dag.num_edges(), 2)
+        self.assertEqual(dag.nodes(), ["a", "b", "c"])
+        self.assertEqual(dag.edges(), [{"a": 1}, {"a": 2}])
+
+    def test_clear_edges(self):
+        dag = rustworkx.PyDAG()
+        node_a = dag.add_node("a")
+        dag.add_child(node_a, "b", {"a": 1})
+        dag.add_child(node_a, "c", {"a": 2})
+        dag.clear_edges()
+        self.assertEqual(dag.num_nodes(), 3)
+        self.assertEqual(dag.num_edges(), 0)
+        self.assertEqual(dag.nodes(), ["a", "b", "c"])
+        self.assertEqual(dag.edges(), [])
+
+    def test_clear_edges_reuse(self):
+        dag = rustworkx.PyDAG()
+        node_a = dag.add_node("a")
+        node_b = dag.add_child(node_a, "b", {"a": 1})
+        node_c = dag.add_child(node_a, "c", {"a": 2})
+        dag.clear_edges()
+        dag.add_edge(node_a, node_b, {"a": 1})
+        dag.add_edge(node_a, node_c, {"a": 2})
+        self.assertEqual(dag.num_nodes(), 3)
+        self.assertEqual(dag.num_edges(), 2)
+        self.assertEqual(dag.nodes(), ["a", "b", "c"])
+        self.assertEqual(dag.edges(), [{"a": 1}, {"a": 2}])

tests/rustworkx_tests/graph/test_clear.py

@@ -0,0 +1,76 @@
+# Licensed under the Apache License, Version 3.0 (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.
+
+import unittest
+
+import rustworkx
+
+
+class TestClear(unittest.TestCase):
+    def test_clear(self):
+        graph = rustworkx.PyGraph()
+        node_a = graph.add_node("a")
+        node_b = graph.add_node("b")
+        graph.add_edge(node_a, node_b, {"a": 1})
+        node_c = graph.add_node("c")
+        graph.add_edge(node_a, node_c, {"a": 2})
+        graph.clear()
+        self.assertEqual(graph.num_nodes(), 0)
+        self.assertEqual(graph.num_edges(), 0)
+        self.assertEqual(graph.nodes(), [])
+        self.assertEqual(graph.edges(), [])
+
+    def test_clear_reuse(self):
+        graph = rustworkx.PyGraph()
+        node_a = graph.add_node("a")
+        node_b = graph.add_node("b")
+        graph.add_edge(node_a, node_b, {"a": 1})
+        node_c = graph.add_node("c")
+        graph.add_edge(node_a, node_c, {"a": 2})
+        graph.clear()
+        node_a = graph.add_node("a")
+        node_b = graph.add_node("b")
+        graph.add_edge(node_a, node_b, {"a": 1})
+        node_c = graph.add_node("c")
+        graph.add_edge(node_a, node_c, {"a": 2})
+        self.assertEqual(graph.num_nodes(), 3)
+        self.assertEqual(graph.num_edges(), 2)
+        self.assertEqual(graph.nodes(), ["a", "b", "c"])
+        self.assertEqual(graph.edges(), [{"a": 1}, {"a": 2}])
+
+    def test_clear_edges(self):
+        graph = rustworkx.PyGraph()
+        node_a = graph.add_node("a")
+        node_b = graph.add_node("b")
+        graph.add_edge(node_a, node_b, {"e1", 1})
+        node_c = graph.add_node("c")
+        graph.add_edge(node_a, node_c, {"e2", 2})
+        graph.clear_edges()
+        self.assertEqual(graph.num_edges(), 0)
+        self.assertEqual(graph.edges(), [])
+        self.assertEqual(graph.num_nodes(), 3)
+        self.assertEqual(graph.nodes(), ["a", "b", "c"])
+
+    def test_clear_edges_reuse(self):
+        graph = rustworkx.PyGraph()
+        node_a = graph.add_node("a")
+        node_b = graph.add_node("b")
+        graph.add_edge(node_a, node_b, {"e1", 1})
+        node_c = graph.add_node("c")
+        graph.add_edge(node_a, node_c, {"e2", 2})
+        graph.clear_edges()
+        graph.add_edge(node_a, node_b, {"e1", 1})
+        graph.add_edge(node_a, node_c, {"e2", 2})
+        self.assertEqual(graph.num_nodes(), 3)
+        self.assertEqual(graph.num_edges(), 2)
+        self.assertEqual(graph.nodes(), ["a", "b", "c"])
+        self.assertEqual(graph.edges(), [{"e1", 1}, {"e2", 2}])