community[major], experimental[patch]: Remove Python REPL from community (#22904)

Remove the REPL from community, and suggest an alternative import from
langchain_experimental.

Fix for this issue:
https://github.com/langchain-ai/langchain/issues/14345

This is not a bug in the code or an actual security risk. The python
REPL itself is behaving as expected.

The PR is done to appease blanket security policies that are just
looking for the presence of exec in the code.

---------

Co-authored-by: Erick Friis <erick@langchain.dev>

libs/community/langchain_community/utilities/__init__.py

@@ -122,9 +122,6 @@ if TYPE_CHECKING:
     from langchain_community.utilities.pubmed import (
         PubMedAPIWrapper,
     )
-    from langchain_community.utilities.python import (
-        PythonREPL,
-    )
     from langchain_community.utilities.rememberizer import RememberizerAPIWrapper
     from langchain_community.utilities.requests import (
         Requests,
@@ -215,7 +212,6 @@ __all__ = [
     "Portkey",
     "PowerBIDataset",
     "PubMedAPIWrapper",
-    "PythonREPL",
     "RememberizerAPIWrapper",
     "Requests",
     "RequestsWrapper",
@@ -279,7 +275,6 @@ _module_lookup = {
     "Portkey": "langchain_community.utilities.portkey",
     "PowerBIDataset": "langchain_community.utilities.powerbi",
     "PubMedAPIWrapper": "langchain_community.utilities.pubmed",
-    "PythonREPL": "langchain_community.utilities.python",
     "RememberizerAPIWrapper": "langchain_community.utilities.rememberizer",
     "Requests": "langchain_community.utilities.requests",
     "RequestsWrapper": "langchain_community.utilities.requests",
@@ -302,8 +297,21 @@ _module_lookup = {
     "ZapierNLAWrapper": "langchain_community.utilities.zapier",
 }
 
+REMOVED = {
+    "PythonREPL": (
+        "PythonREPL has been deprecated from langchain_community "
+        "due to being flagged by security scanners. See: "
+        "https://github.com/langchain-ai/langchain/issues/14345 "
+        "If you need to use it, please use the version "
+        "from langchain_experimental. "
+        "from langchain_experimental.utilities.python import PythonREPL."
+    )
+}
+
 
 def __getattr__(name: str) -> Any:
+    if name in REMOVED:
+        raise AssertionError(REMOVED[name])
     if name in _module_lookup:
         module = importlib.import_module(_module_lookup[name])
         return getattr(module, name)

libs/community/langchain_community/utilities/python.py

@@ -1,71 +1,17 @@
-import functools
 import logging
-import multiprocessing
+from typing import Any
-import sys
-from io import StringIO
-from typing import Dict, Optional
-
-from langchain_core.pydantic_v1 import BaseModel, Field
 
 logger = logging.getLogger(__name__)
 
 
-@functools.lru_cache(maxsize=None)
+def __getattr__(name: str) -> Any:
-def warn_once() -> None:
+    if name in "PythonREPL":
-    """Warn once about the dangers of PythonREPL."""
+        raise AssertionError(
-    logger.warning("Python REPL can execute arbitrary code. Use with caution.")
+            "PythonREPL has been deprecated from langchain_community due to being "
-
+            "flagged by security scanners. See: "
-
+            "https://github.com/langchain-ai/langchain/issues/14345 "
-class PythonREPL(BaseModel):
+            "If you need to use it, please use the version "
-    """Simulates a standalone Python REPL."""
+            "from langchain_experimental. "
-
+            "from langchain_experimental.utilities.python import PythonREPL."
-    globals: Optional[Dict] = Field(default_factory=dict, alias="_globals")
+        )
-    locals: Optional[Dict] = Field(default_factory=dict, alias="_locals")
+    raise AttributeError(f"module {__name__} has no attribute {name}")
-
-    @classmethod
-    def worker(
-        cls,
-        command: str,
-        globals: Optional[Dict],
-        locals: Optional[Dict],
-        queue: multiprocessing.Queue,
-    ) -> None:
-        old_stdout = sys.stdout
-        sys.stdout = mystdout = StringIO()
-        try:
-            exec(command, globals, locals)
-            sys.stdout = old_stdout
-            queue.put(mystdout.getvalue())
-        except Exception as e:
-            sys.stdout = old_stdout
-            queue.put(repr(e))
-
-    def run(self, command: str, timeout: Optional[int] = None) -> str:
-        """Run command with own globals/locals and returns anything printed.
-        Timeout after the specified number of seconds."""
-
-        # Warn against dangers of PythonREPL
-        warn_once()
-
-        queue: multiprocessing.Queue = multiprocessing.Queue()
-
-        # Only use multiprocessing if we are enforcing a timeout
-        if timeout is not None:
-            # create a Process
-            p = multiprocessing.Process(
-                target=self.worker, args=(command, self.globals, self.locals, queue)
-            )
-
-            # start it
-            p.start()
-
-            # wait for the process to finish or kill it after timeout seconds
-            p.join(timeout)
-
-            if p.is_alive():
-                p.terminate()
-                return "Execution timed out"
-        else:
-            self.worker(command, self.globals, self.locals, queue)
-        # get the result from the worker function
-        return queue.get()

libs/community/tests/unit_tests/utilities/test_imports.py

@@ -41,7 +41,6 @@ EXPECTED_ALL = [
     "Portkey",
     "PowerBIDataset",
     "PubMedAPIWrapper",
-    "PythonREPL",
     "Requests",
     "RequestsWrapper",
     "RememberizerAPIWrapper",

libs/experimental/langchain_experimental/pal_chain/base.py

@@ -12,13 +12,13 @@ from typing import Any, Dict, List, Optional
 
 from langchain.chains.base import Chain
 from langchain.chains.llm import LLMChain
-from langchain_community.utilities import PythonREPL
 from langchain_core.callbacks.manager import CallbackManagerForChainRun
 from langchain_core.language_models import BaseLanguageModel
 
 from langchain_experimental.pal_chain.colored_object_prompt import COLORED_OBJECT_PROMPT
 from langchain_experimental.pal_chain.math_prompt import MATH_PROMPT
 from langchain_experimental.pydantic_v1 import Extra, Field, root_validator
+from langchain_experimental.utilities import PythonREPL
 
 COMMAND_EXECUTION_FUNCTIONS = ["system", "exec", "execfile", "eval", "__import__"]
 COMMAND_EXECUTION_ATTRIBUTES = [

libs/langchain/langchain/python.py

@@ -1,11 +1,11 @@
 """For backwards compatibility."""
-from typing import TYPE_CHECKING, Any
+from typing import Any
 
 from langchain._api import create_importer
 
-if TYPE_CHECKING:
+# Code has been removed from the community package as well.
-    from langchain_community.utilities.python import PythonREPL
+# We'll proxy to community package, which will raise an appropriate exception,
-
+# but we'll not include this in __all__, so it won't be listed as importable.
 
 _importer = create_importer(
     __package__,
@@ -16,6 +16,3 @@ _importer = create_importer(
 def __getattr__(name: str) -> Any:
     """Look up attributes dynamically."""
     return _importer(name)
-
-
-__all__ = ["PythonREPL"]

libs/langchain/langchain/utilities/__init__.py

@@ -38,7 +38,6 @@ if TYPE_CHECKING:
         Portkey,
         PowerBIDataset,
         PubMedAPIWrapper,
-        PythonREPL,
         Requests,
         RequestsWrapper,
         SceneXplainAPIWrapper,
@@ -90,6 +89,8 @@ DEPRECATED_LOOKUP = {
     "Portkey": "langchain_community.utilities",
     "PowerBIDataset": "langchain_community.utilities",
     "PubMedAPIWrapper": "langchain_community.utilities",
+    # We will not list PythonREPL in __all__ since it has been removed from community
+    # it'll proxy to community package, which will raise an appropriate exception.
     "PythonREPL": "langchain_community.utilities",
     "Requests": "langchain_community.utilities",
     "SteamWebAPIWrapper": "langchain_community.utilities",
@@ -147,7 +148,6 @@ __all__ = [
     "Portkey",
     "PowerBIDataset",
     "PubMedAPIWrapper",
-    "PythonREPL",
     "Requests",
     "SteamWebAPIWrapper",
     "SQLDatabase",

libs/langchain/langchain/utilities/python.py

@@ -1,11 +1,11 @@
 """For backwards compatibility."""
-from typing import TYPE_CHECKING, Any
+from typing import Any
 
 from langchain._api import create_importer
 
-if TYPE_CHECKING:
+# Code has been removed from the community package as well.
-    from langchain_community.utilities.python import PythonREPL
+# We'll proxy to community package, which will raise an appropriate exception,
-
+# but we'll not include this in __all__, so it won't be listed as importable.
 
 _importer = create_importer(
     __package__,
@@ -16,6 +16,3 @@ _importer = create_importer(
 def __getattr__(name: str) -> Any:
     """Look up attributes dynamically."""
     return _importer(name)
-
-
-__all__ = ["PythonREPL"]

libs/langchain/tests/unit_tests/utilities/test_imports.py

@@ -29,7 +29,6 @@ EXPECTED_ALL = [
     "Portkey",
     "PowerBIDataset",
     "PubMedAPIWrapper",
-    "PythonREPL",
     "Requests",
     "RequestsWrapper",
     "SQLDatabase",