Persistent Bash Shell (#3580)

Clean up linting and make more idiomatic by using an output parser

---------

Co-authored-by: FergusFettes <fergusfettes@gmail.com>

docs/modules/chains/examples/llm_bash.ipynb

@@ -24,8 +24,8 @@
       "\n",
       "```bash\n",
       "echo \"Hello World\"\n",
-      "```\u001b[0m['```bash', 'echo \"Hello World\"', '```']\n",
-      "\n",
+      "```\u001b[0m\n",
+      "Code: \u001b[33;1m\u001b[1;3m['echo \"Hello World\"']\u001b[0m\n",
       "Answer: \u001b[33;1m\u001b[1;3mHello World\n",
       "\u001b[0m\n",
       "\u001b[1m> Finished chain.\u001b[0m\n"
@@ -65,7 +65,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 28,
+   "execution_count": 2,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -93,7 +93,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 29,
+   "execution_count": 3,
    "metadata": {},
    "outputs": [
     {
@@ -107,8 +107,8 @@
       "\n",
       "```bash\n",
       "printf \"Hello World\\n\"\n",
-      "```\u001b[0m['```bash', 'printf \"Hello World\\\\n\"', '```']\n",
-      "\n",
+      "```\u001b[0m\n",
+      "Code: \u001b[33;1m\u001b[1;3m['printf \"Hello World\\\\n\"']\u001b[0m\n",
       "Answer: \u001b[33;1m\u001b[1;3mHello World\n",
       "\u001b[0m\n",
       "\u001b[1m> Finished chain.\u001b[0m\n"
@@ -120,7 +120,7 @@
        "'Hello World\\n'"
       ]
      },
-     "execution_count": 29,
+     "execution_count": 3,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -132,6 +132,114 @@
     "\n",
     "bash_chain.run(text)"
    ]
+  },
+  {
+   "attachments": {},
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Persistent Terminal\n",
+    "\n",
+    "By default, the chain will run in a separate subprocess each time it is called. This behavior can be changed by instantiating with a persistent bash process."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      "\n",
+      "\u001b[1m> Entering new LLMBashChain chain...\u001b[0m\n",
+      "List the current directory then move up a level.\u001b[32;1m\u001b[1;3m\n",
+      "\n",
+      "```bash\n",
+      "ls\n",
+      "cd ..\n",
+      "```\u001b[0m\n",
+      "Code: \u001b[33;1m\u001b[1;3m['ls', 'cd ..']\u001b[0m\n",
+      "Answer: \u001b[33;1m\u001b[1;3mapi.ipynb\t\t\tllm_summarization_checker.ipynb\n",
+      "constitutional_chain.ipynb\tmoderation.ipynb\n",
+      "llm_bash.ipynb\t\t\topenai_openapi.yaml\n",
+      "llm_checker.ipynb\t\topenapi.ipynb\n",
+      "llm_math.ipynb\t\t\tpal.ipynb\n",
+      "llm_requests.ipynb\t\tsqlite.ipynb\u001b[0m\n",
+      "\u001b[1m> Finished chain.\u001b[0m\n"
+     ]
+    },
+    {
+     "data": {
+      "text/plain": [
+       "'api.ipynb\\t\\t\\tllm_summarization_checker.ipynb\\r\\nconstitutional_chain.ipynb\\tmoderation.ipynb\\r\\nllm_bash.ipynb\\t\\t\\topenai_openapi.yaml\\r\\nllm_checker.ipynb\\t\\topenapi.ipynb\\r\\nllm_math.ipynb\\t\\t\\tpal.ipynb\\r\\nllm_requests.ipynb\\t\\tsqlite.ipynb'"
+      ]
+     },
+     "execution_count": 4,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "from langchain.utilities.bash import BashProcess\n",
+    "\n",
+    "\n",
+    "persistent_process = BashProcess(persistent=True)\n",
+    "bash_chain = LLMBashChain.from_bash_process(llm=llm, bash_process=persistent_process, verbose=True)\n",
+    "\n",
+    "text = \"List the current directory then move up a level.\"\n",
+    "\n",
+    "bash_chain.run(text)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      "\n",
+      "\u001b[1m> Entering new LLMBashChain chain...\u001b[0m\n",
+      "List the current directory then move up a level.\u001b[32;1m\u001b[1;3m\n",
+      "\n",
+      "```bash\n",
+      "ls\n",
+      "cd ..\n",
+      "```\u001b[0m\n",
+      "Code: \u001b[33;1m\u001b[1;3m['ls', 'cd ..']\u001b[0m\n",
+      "Answer: \u001b[33;1m\u001b[1;3mexamples\t\tgetting_started.ipynb\tindex_examples\n",
+      "generic\t\t\thow_to_guides.rst\u001b[0m\n",
+      "\u001b[1m> Finished chain.\u001b[0m\n"
+     ]
+    },
+    {
+     "data": {
+      "text/plain": [
+       "'examples\\t\\tgetting_started.ipynb\\tindex_examples\\r\\ngeneric\\t\\t\\thow_to_guides.rst'"
+      ]
+     },
+     "execution_count": 5,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "# Run the same command again and see that the state is maintained between calls\n",
+    "bash_chain.run(text)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
   }
  ],
  "metadata": {
@@ -150,7 +258,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.10.6"
+   "version": "3.8.16"
   }
  },
  "nbformat": 4,