van_der_pol: Add self-contained example Python bindings

bindings/pydrake/examples/BUILD.bazel

@@ -92,6 +92,8 @@ drake_pybind_library(
     ],
 )
 
+# N.B. This is duplicated from `//examples/van_der_pol`, and will be removed
+# as part of (#9645).
 drake_pybind_library(
     name = "van_der_pol_py",
     cc_deps = [

bindings/pydrake/examples/test/van_der_pol_test.py

@@ -1,3 +1,6 @@
+# N.B. This is duplicated from `//examples/van_der_pol`, and will be removed
+# as part of (#9645).
+
 from __future__ import print_function
 
 import unittest

bindings/pydrake/examples/van_der_pol_py.cc

@@ -1,3 +1,6 @@
+// N.B. This is duplicated from `//examples/van_der_pol`, and will be removed
+// as part of (#9645).
+
 #include "pybind11/pybind11.h"
 
 #include "drake/bindings/pydrake/documentation_pybind.h"

examples/BUILD.bazel

@@ -65,6 +65,7 @@ filegroup(
 # issues #4224 and #1766).
 INSTALLED_EXAMPLES = [
     "//examples/kuka_iiwa_arm",
+    "//examples/van_der_pol",
 ]
 
 install(

examples/van_der_pol/BUILD.bazel

@@ -1,12 +1,26 @@
 # -*- python -*-
 
 load(
-    "//tools:drake.bzl",
+    "@drake//tools/skylark:drake_cc.bzl",
     "drake_cc_binary",
     "drake_cc_googletest",
     "drake_cc_library",
 )
-load("//tools/lint:lint.bzl", "add_lint_tests")
+load(
+    "@drake//tools/skylark:drake_py.bzl",
+    "drake_py_binary",
+)
+load(
+    "@drake//tools/skylark:pybind.bzl",
+    "drake_pybind_library",
+    "generate_pybind_documentation_header",
+)
+load(
+    "@drake//tools/install:install.bzl",
+    "generate_install_test_file",
+    "install",
+)
+load("@drake//tools/lint:lint.bzl", "add_lint_tests")
 
 drake_cc_library(
     name = "van_der_pol",
@@ -43,4 +57,70 @@ drake_cc_googletest(
     ],
 )
 
+# TODO(eric.cousineau): Try to hide more of these details for authoring Python
+# binding examples.
+
+generate_pybind_documentation_header(
+    name = "generate_documentation_pybind",
+    out = "documentation_pybind.h",
+    root_name = "van_der_pol_doc",
+    targets = [":van_der_pol"],
+)
+
+drake_cc_library(
+    name = "documentation_pybind",
+    hdrs = ["documentation_pybind.h"],
+    tags = ["nolint"],
+)
+
+van_der_pol_py = drake_pybind_library(
+    name = "van_der_pol_py",
+    # This is specific to `pydrake`.
+    add_install = 0,
+    cc_deps = [":documentation_pybind"],
+    cc_so_name = "van_der_pol",
+    cc_srcs = [
+        # To avoid ODR with static upstream dependencies of `:van_der_pol`, we
+        # will recompile the relevant source files.
+        "van_der_pol.cc",
+        "van_der_pol.h",
+        "van_der_pol_py.cc",
+    ],
+    py_deps = ["//bindings/pydrake/systems:analysis_py"],
+)
+
+drake_py_binary(
+    name = "van_der_pol_py_example",
+    srcs = ["van_der_pol_example.py"],
+    add_test_rule = 1,
+    # N.B. Imports are only required by this binary in Bazel runfiles, because
+    # Bazel somehow munges the paths such that we do not already have access to
+    # `van_der_pol_py`. This will not be an issue for installation.
+    imports = ["."],
+    deps = ["van_der_pol_py"],
+)
+
+generate_install_test_file(
+    name = "test/van_der_pol_installed_test.py",
+    cmd = "{python} {install_dir}/share/drake/examples/van_der_pol/van_der_pol_example.py",  # noqa
+)
+
+install(
+    name = "install",
+    install_tests = [
+        ":test/van_der_pol_installed_test.py",
+    ],
+    targets = [
+        van_der_pol_py.cc_so_target,
+    ],
+    library_dest = "share/drake/examples/van_der_pol",
+    # N.B. We use `data` so that we may install the Python files; we should
+    # not be installing the Bazel-generated wrapper files.
+    data = [
+        "van_der_pol_example.py",
+    ],
+    data_dest = "share/drake/examples/van_der_pol",
+    visibility = ["//visibility:public"],
+)
+
 add_lint_tests()

examples/van_der_pol/van_der_pol_example.py

@@ -0,0 +1,28 @@
+"""Provides example of running van_der_pol bindings.
+
+To run from an installation, please execute:
+
+    python {install_dir}/share/drake/examples/van_der_pol/van_der_pol_example.py  # noqa
+"""
+
+from __future__ import print_function
+
+from pydrake.systems.analysis import Simulator
+
+from van_der_pol import VanDerPolOscillator
+
+
+van_der_pol = VanDerPolOscillator()
+
+# Create the simulator.
+simulator = Simulator(van_der_pol)
+context = simulator.get_mutable_context()
+
+# Set the initial state.
+state = context.get_mutable_continuous_state_vector()
+state.SetFromVector([0., 2.])
+
+# Simulate (and make sure the state actually changes).
+initial_state = state.CopyToVector()
+simulator.StepTo(1.0)
+print("Final state: {}".format(state.CopyToVector()))

examples/van_der_pol/van_der_pol_py.cc

@@ -0,0 +1,32 @@
+#include "pybind11/pybind11.h"
+
+#include "drake/bindings/pydrake/pydrake_pybind.h"
+#include "drake/examples/van_der_pol/documentation_pybind.h"
+#include "drake/examples/van_der_pol/van_der_pol.h"
+
+namespace drake {
+namespace pydrake {
+
+PYBIND11_MODULE(van_der_pol, m) {
+  // NOLINTNEXTLINE(build/namespaces): Emulate placement in namespace.
+  using namespace drake::systems;
+  // NOLINTNEXTLINE(build/namespaces): Emulate placement in namespace.
+  using namespace drake::examples::van_der_pol;
+  constexpr auto& doc = van_der_pol_doc.drake.examples.van_der_pol;
+
+  m.doc() = "Bindings for the van_der_pol example.";
+
+  py::module::import("pydrake.systems.framework");
+
+  // TODO(eric.cousineau): At present, we only bind doubles.
+  // In the future, we will bind more scalar types, and enable scalar
+  // conversion.
+  using T = double;
+
+  py::class_<VanDerPolOscillator<T>, LeafSystem<T>>(m, "VanDerPolOscillator",
+    doc.VanDerPolOscillator.doc)
+      .def(py::init<>(), doc.VanDerPolOscillator.ctor.doc_3);
+}
+
+}  // namespace pydrake
+}  // namespace drake