Source code for langchain_experimental.tools.python.tool
"""A tool for running python code in a REPL."""
import ast
import asyncio
import re
import sys
from contextlib import redirect_stdout
from io import StringIO
from typing import Any, Dict, Optional, Type
from langchain.callbacks.manager import (
AsyncCallbackManagerForToolRun,
CallbackManagerForToolRun,
)
from langchain.pydantic_v1 import BaseModel, Field, root_validator
from langchain.tools.base import BaseTool
from langchain_experimental.utilities.python import PythonREPL
def _get_default_python_repl() -> PythonREPL:
return PythonREPL(_globals=globals(), _locals=None)
[docs]def sanitize_input(query: str) -> str:
"""Sanitize input to the python REPL.
Remove whitespace, backtick & python (if llm mistakes python console as terminal)
Args:
query: The query to sanitize
Returns:
str: The sanitized query
"""
# Removes `, whitespace & python from start
query = re.sub(r"^(\s|`)*(?i:python)?\s*", "", query)
# Removes whitespace & ` from end
query = re.sub(r"(\s|`)*$", "", query)
return query
[docs]class PythonREPLTool(BaseTool):
"""A tool for running python code in a REPL."""
name: str = "Python_REPL"
description: str = (
"A Python shell. Use this to execute python commands. "
"Input should be a valid python command. "
"If you want to see the output of a value, you should print it out "
"with `print(...)`."
)
python_repl: PythonREPL = Field(default_factory=_get_default_python_repl)
sanitize_input: bool = True
def _run(
self,
query: str,
run_manager: Optional[CallbackManagerForToolRun] = None,
) -> Any:
"""Use the tool."""
if self.sanitize_input:
query = sanitize_input(query)
return self.python_repl.run(query)
async def _arun(
self,
query: str,
run_manager: Optional[AsyncCallbackManagerForToolRun] = None,
) -> Any:
"""Use the tool asynchronously."""
if self.sanitize_input:
query = sanitize_input(query)
loop = asyncio.get_running_loop()
result = await loop.run_in_executor(None, self.run, query)
return result
[docs]class PythonAstREPLTool(BaseTool):
"""A tool for running python code in a REPL."""
name: str = "python_repl_ast"
description: str = (
"A Python shell. Use this to execute python commands. "
"Input should be a valid python command. "
"When using this tool, sometimes output is abbreviated - "
"make sure it does not look abbreviated before using it in your answer."
)
globals: Optional[Dict] = Field(default_factory=dict)
locals: Optional[Dict] = Field(default_factory=dict)
sanitize_input: bool = True
args_schema: Type[BaseModel] = PythonInputs
@root_validator(pre=True)
def validate_python_version(cls, values: Dict) -> Dict:
"""Validate valid python version."""
if sys.version_info < (3, 9):
raise ValueError(
"This tool relies on Python 3.9 or higher "
"(as it uses new functionality in the `ast` module, "
f"you have Python version: {sys.version}"
)
return values
def _run(
self,
query: str,
run_manager: Optional[CallbackManagerForToolRun] = None,
) -> str:
"""Use the tool."""
try:
if self.sanitize_input:
query = sanitize_input(query)
tree = ast.parse(query)
module = ast.Module(tree.body[:-1], type_ignores=[])
exec(ast.unparse(module), self.globals, self.locals) # type: ignore
module_end = ast.Module(tree.body[-1:], type_ignores=[])
module_end_str = ast.unparse(module_end) # type: ignore
io_buffer = StringIO()
try:
with redirect_stdout(io_buffer):
ret = eval(module_end_str, self.globals, self.locals)
if ret is None:
return io_buffer.getvalue()
else:
return ret
except Exception:
with redirect_stdout(io_buffer):
exec(module_end_str, self.globals, self.locals)
return io_buffer.getvalue()
except Exception as e:
return "{}: {}".format(type(e).__name__, str(e))
async def _arun(
self,
query: str,
run_manager: Optional[AsyncCallbackManagerForToolRun] = None,
) -> Any:
"""Use the tool asynchronously."""
loop = asyncio.get_running_loop()
result = await loop.run_in_executor(None, self._run, query)
return result