Add Python interop sample notebook (#2066)

This adds a Jupyter notebook sample for invoking Q# callables from
Python. I confirmed the new notebook runs in integration tests as
expected.

Author: swernli

samples/notebooks/project.ipynb

@@ -42,11 +42,32 @@
     "\n",
     "Sample.Main()\n"
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "5fad86c4",
+   "metadata": {},
+   "source": [
+    "The callables from the project are also available under `qsharp.code` and can be called or imported from Python."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "423b6fc4",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from qsharp.code.Sample import Main\n",
+    "\n",
+    "res = Main()\n",
+    "print(f\"Got return value from Q# code: {res}\")"
+   ]
   }
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 3 (ipykernel)",
+   "display_name": "Python 3",
    "language": "python",
    "name": "python3"
   },
@@ -60,7 +81,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.11.6"
+   "version": "3.11.11"
   }
  },
  "nbformat": 4,

samples/notebooks/sample.ipynb

@@ -10,12 +10,6 @@
     "This enables the `%%qsharp` magic and initializes a Q# interpreter singleton."
    ]
   },
-  {
-   "cell_type": "markdown",
-   "id": "ed1b75bf",
-   "metadata": {},
-   "source": []
-  },
   {
    "cell_type": "code",
    "execution_count": null,
@@ -69,7 +63,7 @@
    "source": [
     "`qsharp.eval()` does the same thing as the `%%qsharp` magic.\n",
     "\n",
-    "`DumpMachine()` and `Message()` print to stdout and get displayed in the notebook as plain text"
+    "`DumpMachine()` and `Message()` print to stdout and get displayed in the notebook as plain text."
    ]
   },
   {
@@ -84,6 +78,24 @@
     "qsharp.eval(\"Main()\")\n"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "id": "19f4ef6d",
+   "metadata": {},
+   "source": [
+    "`qsharp.code` provides direct access to simulating callables defined in Q#."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "30b92222",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "qsharp.code.Main()"
+   ]
+  },
   {
    "cell_type": "markdown",
    "id": "a3bde193",
@@ -256,7 +268,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 11,
    "id": "eb3cd29f",
    "metadata": {
     "vscode": {
@@ -382,7 +394,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 14,
    "id": "9b85eb2d",
    "metadata": {
     "vscode": {
@@ -414,6 +426,106 @@
    "source": [
     "qsharp.run(\"Bad()\", 10)\n"
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "9f738245",
+   "metadata": {},
+   "source": [
+    "When invoked from Python, arguments to Q# callables are converted from their Python type to the expected Q# type. If an argument cannot be converted to the right type, it will trigger a runtime exception."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "9ae2729d",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "qsharp.eval(\"\"\"\n",
+    "    function AddTwoInts(a : Int, b : Int) : Int {\n",
+    "        return a + b;\n",
+    "    }\n",
+    "    \"\"\")\n",
+    "\n",
+    "from qsharp.code import AddTwoInts\n",
+    "\n",
+    "print(AddTwoInts(2, 3))\n",
+    "\n",
+    "try:\n",
+    "    AddTwoInts(2, 3.0)\n",
+    "except TypeError as e:\n",
+    "    print(f\"TypeError: {e}\")"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "0f0795e9",
+   "metadata": {},
+   "source": [
+    "If you define any Q# callables in a namespace (or when initializing with a Q# project), those callables will be exposed with a matching hierarchy of modules in Python:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "e7b84a41",
+   "metadata": {
+    "vscode": {
+     "languageId": "qsharp"
+    }
+   },
+   "outputs": [],
+   "source": [
+    "%%qsharp\n",
+    "\n",
+    "import Std.Diagnostics.DumpMachine;\n",
+    "namespace Foo {\n",
+    "    operation Bar() : Unit {\n",
+    "        use qs = Qubit[2];\n",
+    "        for q in qs {\n",
+    "            H(q);\n",
+    "        }\n",
+    "        DumpMachine();\n",
+    "        ResetAll(qs);\n",
+    "    }\n",
+    "}"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "5591587c",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from qsharp.code.Foo import Bar\n",
+    "\n",
+    "Bar()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "020b244b",
+   "metadata": {},
+   "source": [
+    "If you run `qsharp.init()`, the compiler and simulator state are reset and all functions exposed into Python are cleared:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "3d73c247",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "qsharp.init()\n",
+    "\n",
+    "try:\n",
+    "    Bar()\n",
+    "except qsharp.QSharpError as e:\n",
+    "    print(f\"QsharpError: {e}\")"
+   ]
   }
  ],
  "metadata": {
@@ -432,7 +544,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.12.1"
+   "version": "3.11.11"
   }
  },
  "nbformat": 4,

samples/python_interop/generating_n_random_bits/RunGenerateRandom.py

@@ -2,10 +2,10 @@
 
 qsharp.init(project_root=".")
 
+from qsharp.code.GenerateRandomNumbers import GenerateRandomNumbers
+
 nQubits = input("Enter the number of random bits to be generated: ")
-(results, number) = qsharp.eval(
-    f"GenerateRandomNumbers.GenerateRandomNumbers({nQubits})"
-)
+(results, number) = GenerateRandomNumbers(int(nQubits))
 
 count = 0
 for result in results: