LLMMathChain or PALChain gives Generated code is not valid python code

[whoami02]

Checked other resources

• I added a very descriptive title to this question.
• I searched the LangChain documentation with the integrated search.
• I used the GitHub search to find a similar question and didn't find it.

Commit to Help

• I commit to help with one of those options 👆

Example Code

from langchain.chains.llm_math.base import LLMMathChain
from langchain_community.llms.llamacpp import LlamaCpp
from langchain.prompts import PromptTemplate
from langchain.chat_models.anthropic import ChatAnthropic
from new_prompt import math
from langchain_experimental.pal_chain.base import PALChain

claude = ChatAnthropic(
    model_name="claude-2",
    anthropic_api_key=os.getenv("ANTHROPIC_API_KEY"),
    temperature=0.05,
    streaming=True,
    verbose=True,
)
palchain.invoke("Jan has three times the number of pets as Marcia. Marcia has two more pets than Cindy. If Cindy has four pets, how many total pets do the three have?")
palchain = PALChain.from_math_prompt(llm=claude, verbose=True)

Description

I am trying to use math-chain or pal-chain as a custom tool for my react agent, however when I try to run the chain. I am getting the following output with erros

> Entering new PALChain chain...
 Okay, let's think through this step-by-step:
* Cindy has 4 pets
* Marcia has 2 more pets than Cindy, so Marcia has 4 + 2 = 6 pets
* Jan has 3 times as many pets as Marcia 
* Marcia has 6 pets
* 3 times 6 is 18
* So Jan has 18 pets
* In total:
    * Cindy has 4 pets 
    * Marcia has 6 pets
    * Jan has 18 pets
* 4 + 6 + 18 = 28
---------------------------------------------------------------------------
IndentationError                          Traceback (most recent call last)
File [e:\.venv\Lib\site-packages\langchain_experimental\pal_chain\base.py:173](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:173), in PALChain.validate_code(cls, code, code_validations)
    [172](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:172) try:
--> [173](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:173)     code_tree = ast.parse(code)
    [174](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:174) except (SyntaxError, UnicodeDecodeError):

File [~\AppData\Local\Programs\Python\Python311\Lib\ast.py:50](https://file+.vscode-resource.vscode-cdn.net/e%3A/AW/LLMs/sql_bot/~/AppData/Local/Programs/Python/Python311/Lib/ast.py:50), in parse(source, filename, mode, type_comments, feature_version)
     [49](https://file+.vscode-resource.vscode-cdn.net/e%3A/AW/LLMs/sql_bot/~/AppData/Local/Programs/Python/Python311/Lib/ast.py:49) # Else it should be an int giving the minor version for 3.x.
---> [50](https://file+.vscode-resource.vscode-cdn.net/e%3A/AW/LLMs/sql_bot/~/AppData/Local/Programs/Python/Python311/Lib/ast.py:50) return compile(source, filename, mode, flags,
     [51](https://file+.vscode-resource.vscode-cdn.net/e%3A/AW/LLMs/sql_bot/~/AppData/Local/Programs/Python/Python311/Lib/ast.py:51)                _feature_version=feature_version)

IndentationError: unexpected indent (<unknown>, line 1)

During handling of the above exception, another exception occurred:

ValueError                                Traceback (most recent call last)
Cell In[16], [line 1](vscode-notebook-cell:?execution_count=16&line=1)
----> [1](vscode-notebook-cell:?execution_count=16&line=1) palchain.invoke("Jan has three times the number of pets as Marcia. Marcia has two more pets than Cindy. If Cindy has four pets, how many total pets do the three have?")

File [e:\.venv\Lib\site-packages\langchain\chains\base.py:162](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:162), in Chain.invoke(self, input, config, **kwargs)
    [160](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:160) except BaseException as e:
    [161](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:161)     run_manager.on_chain_error(e)
--> [162](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:162)     raise e
    [163](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:163) run_manager.on_chain_end(outputs)
    [164](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:164) final_outputs: Dict[str, Any] = self.prep_outputs(
    [165](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:165)     inputs, outputs, return_only_outputs
    [166](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:166) )

File [e:\.venv\Lib\site-packages\langchain\chains\base.py:156](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:156), in Chain.invoke(self, input, config, **kwargs)
    [149](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:149) run_manager = callback_manager.on_chain_start(
    [150](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:150)     dumpd(self),
    [151](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:151)     inputs,
    [152](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:152)     name=run_name,
    [153](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:153) )
    [154](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:154) try:
    [155](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:155)     outputs = (
--> [156](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:156)         self._call(inputs, run_manager=run_manager)
    [157](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:157)         if new_arg_supported
    [158](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:158)         else self._call(inputs)
    [159](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:159)     )
    [160](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:160) except BaseException as e:
    [161](file:///E:/.venv/Lib/site-packages/langchain/chains/base.py:161)     run_manager.on_chain_error(e)

File [e:\.venv\Lib\site-packages\langchain_experimental\pal_chain\base.py:156](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:156), in PALChain._call(self, inputs, run_manager)
    [152](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:152) code = self.llm_chain.predict(
    [153](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:153)     stop=[self.stop], callbacks=_run_manager.get_child(), **inputs
    [154](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:154) )
    [155](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:155) _run_manager.on_text(code, color="green", end="\n", verbose=self.verbose)
--> [156](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:156) PALChain.validate_code(code, self.code_validations)
    [158](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:158) # TODO: look into why mypy thinks PythonREPL's type here is `Any`
    [159](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:159) #       and therefore not callable
    [160](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:160) repl = PythonREPL(
    [161](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:161)     _globals=self.python_globals,
    [162](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:162)     _locals=self.python_locals,
    [163](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:163) )  # type: ignore[misc]

File [e:\.venv\Lib\site-packages\langchain_experimental\pal_chain\base.py:175](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:175), in PALChain.validate_code(cls, code, code_validations)
    [173](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:173)     code_tree = ast.parse(code)
    [174](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:174) except (SyntaxError, UnicodeDecodeError):
--> [175](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:175)     raise ValueError(f"Generated code is not valid python code: {code}")
    [176](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:176) except TypeError:
    [177](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:177)     raise ValueError(
    [178](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:178)         f"Generated code is expected to be a string, "
    [179](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:179)         f"instead found {type(code)}"
    [180](file:///E:/.venv/Lib/site-packages/langchain_experimental/pal_chain/base.py:180)     )

ValueError: Generated code is not valid python code:  Okay, let's think through this step-by-step:
* Cindy has 4 pets
* Marcia has 2 more pets than Cindy, so Marcia has 4 + 2 = 6 pets
* Jan has 3 times as many pets as Marcia 
* Marcia has 6 pets
* 3 times 6 is 18
* So Jan has 18 pets
* In total:
    * Cindy has 4 pets 
    * Marcia has 6 pets
    * Jan has 18 pets
* 4 + 6 + 18 = 28

It is able to solve the question but its giving ValueError rather than printing the answer.
Can anyone help me?

System Info

using langchain == 0.1.3

[dosubot[bot]]

Based on the error traceback you've provided, it seems like the PALChain is trying to parse the generated step-by-step solution to a math problem as Python code, which is causing the ValueError. The validate_code method in the PALChain class is designed to ensure that the generated code is valid Python syntax before it's executed. However, in this case, the generated output is not intended to be Python code, but a human-readable solution to a math problem.

The issue seems to be with the following line of code:

palchain.invoke("Jan has three times the number of pets as Marcia. Marcia has two more pets than Cindy. If Cindy has four pets, how many total pets do the three have?")

Here, you're invoking the PALChain with a math problem, which is expected to return a step-by-step solution. However, the invoke method is designed to generate Python code, not human-readable solutions. This is why the validate_code method is raising a ValueError when it tries to parse the solution as Python code.

To resolve this issue, you might want to consider using a different method or class that's designed to generate human-readable solutions to math problems, rather than Python code. If such a method or class doesn't exist in the LangChain library, you might need to implement it yourself.

Also, please note that you're using an older version of LangChain (v0.1.3). The latest version is v0.1.11. It's possible that this issue has been addressed in a more recent version of the library. I recommend checking the release notes and considering an upgrade to the latest version.

I hope this helps! If you have any other questions or need further clarification, feel free to ask.

Sources

• libs/experimental/langchain_experimental/pal_chain/base.py
• libs/experimental/langchain/experimental/pal_chain/base.py

About Dosu

This response is meant to be useful and save you time. It is not meant to be a precise solution, but rather a starting point for your own research.

Help me be more useful! Please leave a 👍 if this is helpful and 👎 if it is irrelevant.

If you want to continue the conversation, start your reply with @dosu-bot.

[whoami02]

Yes I know why I am getting this error, can you give me a solution for this?

[amritsairam]

@whoami02 Did you find a solution for this

[whoami02]

Unfortunately, I was not able to get anything on this. Solved mathematical part by different approach :)