Issue: Can not import the Langchain modules.

[shivam-36]

Issue you'd like to raise.

I installed "langchain==0.0.27" on a linux machine but i am getting the folowing error when i try to import langchain in a script. Was running this with python 3.7.

/home/s0s06c3/lang/lang_env/bin/python /home/s0s06c3/lang/hugging_lanchain.py Traceback (most recent call last): File "/home/s0s06c3/lang/hugging_lanchain.py", line 2, in <module> from langchain import PromptTemplate, HuggingFaceHub, LLMChain File "/home/s0s06c3/lang/lang_env/lib/python3.7/site-packages/langchain/__init__.py", line 8, in <module> from langchain.agents import MRKLChain, ReActChain, SelfAskWithSearchChain File "/home/s0s06c3/lang/lang_env/lib/python3.7/site-packages/langchain/agents/__init__.py", line 2, in <module> from langchain.agents.agent import Agent File "/home/s0s06c3/lang/lang_env/lib/python3.7/site-packages/langchain/agents/agent.py", line 10, in <module> from langchain.chains.base import Chain File "/home/s0s06c3/lang/lang_env/lib/python3.7/site-packages/langchain/chains/__init__.py", line 2, in <module> from langchain.chains.conversation.base import ConversationChain File "/home/s0s06c3/lang/lang_env/lib/python3.7/site-packages/langchain/chains/conversation/base.py", line 7, in <module> from langchain.chains.conversation.memory import ConversationBufferMemory File "/home/s0s06c3/lang/lang_env/lib/python3.7/site-packages/langchain/chains/conversation/memory.py", line 7, in <module> from langchain.chains.conversation.prompt import SUMMARY_PROMPT File "/home/s0s06c3/lang/lang_env/lib/python3.7/site-packages/langchain/chains/conversation/prompt.py", line 2, in <module> from langchain.prompts.prompt import PromptTemplate File "/home/s0s06c3/lang/lang_env/lib/python3.7/site-packages/langchain/prompts/__init__.py", line 2, in <module> from langchain.prompts.base import BasePromptTemplate File "/home/s0s06c3/lang/lang_env/lib/python3.7/site-packages/langchain/prompts/base.py", line 35, in <module> class BasePromptTemplate(BaseModel, ABC): File "/home/s0s06c3/lang/lang_env/lib/python3.7/site-packages/langchain/prompts/base.py", line 41, in BasePromptTemplate @root_validator() File "/home/s0s06c3/lang/lang_env/lib/python3.7/site-packages/pydantic/deprecated/class_validators.py", line 231, in root_validator code='root-validator-pre-skip', pydantic.errors.PydanticUserError: If you use @root_validatorwith pre=False (the default) you MUST specifyskip_on_failure=True. Note that @root_validatoris deprecated and should be replaced with@model_validator.

I tried setting this up on my local machine as well but there also got the same issue.

Suggestion:

No response

[dosubot[bot]]

Answer generated by a 🤖

Answer

I understand that you're encountering an issue when trying to import the Langchain modules in your Python script. The error message you're seeing is related to the Pydantic library, which Langchain uses. Specifically, the error is about the use of the @root_validator decorator in the BasePromptTemplate class. This issue could be due to a version mismatch between the Pydantic library that Langchain requires and the one installed in your environment.

I suggest trying to install a specific version of Pydantic that might be compatible with Langchain. It's possible that Langchain is using a feature of Pydantic that has been deprecated or altered in the version you currently have installed.

You can try installing an older version of Pydantic to see if that resolves the issue. For instance, you could use the following command:

pip install pydantic==1.8

Please note that this is a potential solution and it might not resolve the issue if Langchain requires a different version of Pydantic. If this doesn't work, it might be necessary to experiment with other versions of Pydantic to find one that is compatible with Langchain.

If you find a version of Pydantic that resolves this issue, it would be beneficial to other users if you could make a pull request to the Langchain repository with the information about the compatible Pydantic version. This could help others who might encounter the same problem in the future.

Sources

• docs/snippets/get_started/quickstart/chains_chat_models.mdx

---

This response is meant to be useful, save you time, and share context. 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.

[devstein]

@shivam-36 The latest version of LangChain is 0.0.222. Try upgrade to the latest and see if that works.

[shivam-36]

@devstein I tried that version and this issue was persisting. For now i upgraded my python version to 3.9 and then installed langchain 0.0.219 . I think the issue is due to some version mismatch in the pydantic module but could not find the exact verson required for langchain.

[RawthiL]

I had this problem with:

langchain==0.0.229
langchainplus-sdk==0.0.20
pydantic==2.0.2
pydantic-core==2.1.2

I had to downgrade pydantic to:

pydantic==1.10.9

Now it works... Not a solution, but a workaround...

[YueqingSheng]

Same issue, however, I am using Pydantic 2 in my project and I am not inclined to use the downgrading method as a solution.

[wnmurphy]

For what it's worth, saw this as well with a Flask server trying to import anything from langchain. The root cause was pydantic. Adding pydantic to pip with a specific version (pydantic==1.10.9) rather than just letting pip install it as a langchain dependency resolved the issue.

My stack trace had a lot of these

File "/Users/neilmurphy/.pyenv/versions/service/lib/python3.9/site-packages/connexion/utils.py", line 116, in get_function_from_name
    module = importlib.import_module(module_name)
  File "/Users/neilmurphy/.pyenv/versions/3.9.14/lib/python3.9/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
  File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 680, in _load_unlocked
  File "/Users/neilmurphy/.pyenv/versions/service/lib/python3.9/site-packages/ddtrace/internal/module.py", line 190, in _exec_module
    self.loader.exec_module(module)

[shivam-36]

Downgrading pydantic is what worked for me too. Closing the issue.

[ragarwal23]

It did not work for me. Please help. Below are snippits of my code.

!pip install pydantic==1.10.9 !pip install langchain !pip install openai

from langchain.llms import OpenAI

[guvkay20]

How is downgrading Pydantic acceptable? Pydantic v1 and v2 are very different