langchain: import langchain with python<=3.9 fails

System Info

platform

$ cat /etc/os-release 
NAME="Ubuntu"
VERSION="20.04.6 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04.6 LTS"
VERSION_ID="20.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=focal
UBUNTU_CODENAME=focal

python

$ python -V
Python 3.9.7

# installed with
asdf install python 3.9.7

problematic dependency (updated after this comment)

# this was updated today.
typing_extensions==4.6.0

dependencies

langchain==0.0.177
openapi-schema-pydantic==1.2.4
pydantic==1.10.7

all the dependencies

$ pip install langchain
Collecting langchain
  Using cached langchain-0.0.177-py3-none-any.whl (877 kB)
Collecting PyYAML>=5.4.1
  Using cached PyYAML-6.0-cp39-cp39-manylinux_2_5_x86_64.manylinux1_x86_64.manylinux_2_12_x86_64.manylinux2010_x86_64.whl (661 kB)
Collecting openapi-schema-pydantic<2.0,>=1.2
  Using cached openapi_schema_pydantic-1.2.4-py3-none-any.whl (90 kB)
Collecting requests<3,>=2
  Using cached requests-2.31.0-py3-none-any.whl (62 kB)
Collecting SQLAlchemy<3,>=1.4
  Using cached SQLAlchemy-2.0.15-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (2.7 MB)
Collecting aiohttp<4.0.0,>=3.8.3
  Using cached aiohttp-3.8.4-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (1.0 MB)
Collecting dataclasses-json<0.6.0,>=0.5.7
  Using cached dataclasses_json-0.5.7-py3-none-any.whl (25 kB)
Collecting async-timeout<5.0.0,>=4.0.0
  Using cached async_timeout-4.0.2-py3-none-any.whl (5.8 kB)
Collecting numexpr<3.0.0,>=2.8.4
  Using cached numexpr-2.8.4-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (380 kB)
Collecting pydantic<2,>=1
  Using cached pydantic-1.10.7-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (3.2 MB)
Collecting numpy<2,>=1
  Using cached numpy-1.24.3-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (17.3 MB)
Collecting tenacity<9.0.0,>=8.1.0
  Using cached tenacity-8.2.2-py3-none-any.whl (24 kB)
Collecting multidict<7.0,>=4.5
  Using cached multidict-6.0.4-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (114 kB)
Collecting attrs>=17.3.0
  Using cached attrs-23.1.0-py3-none-any.whl (61 kB)
Collecting charset-normalizer<4.0,>=2.0
  Using cached charset_normalizer-3.1.0-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (199 kB)
Collecting yarl<2.0,>=1.0
  Using cached yarl-1.9.2-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (269 kB)
Collecting frozenlist>=1.1.1
  Using cached frozenlist-1.3.3-cp39-cp39-manylinux_2_5_x86_64.manylinux1_x86_64.manylinux_2_17_x86_64.manylinux2014_x86_64.whl (158 kB)
Collecting aiosignal>=1.1.2
  Using cached aiosignal-1.3.1-py3-none-any.whl (7.6 kB)
Collecting typing-inspect>=0.4.0
  Using cached typing_inspect-0.8.0-py3-none-any.whl (8.7 kB)
Collecting marshmallow<4.0.0,>=3.3.0
  Using cached marshmallow-3.19.0-py3-none-any.whl (49 kB)
Collecting marshmallow-enum<2.0.0,>=1.5.1
  Using cached marshmallow_enum-1.5.1-py2.py3-none-any.whl (4.2 kB)
Collecting packaging>=17.0
  Using cached packaging-23.1-py3-none-any.whl (48 kB)
Collecting typing-extensions>=4.2.0
  Using cached typing_extensions-4.6.0-py3-none-any.whl (30 kB)
Collecting idna<4,>=2.5
  Using cached idna-3.4-py3-none-any.whl (61 kB)
Collecting urllib3<3,>=1.21.1
  Using cached urllib3-2.0.2-py3-none-any.whl (123 kB)
Collecting certifi>=2017.4.17
  Using cached certifi-2023.5.7-py3-none-any.whl (156 kB)
Collecting greenlet!=0.4.17
  Using cached greenlet-2.0.2-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (610 kB)
Collecting mypy-extensions>=0.3.0
  Using cached mypy_extensions-1.0.0-py3-none-any.whl (4.7 kB)
Installing collected packages: packaging, typing-extensions, mypy-extensions, multidict, marshmallow, idna, frozenlist, yarl, urllib3, typing-inspect, pydantic, numpy, marshmallow-enum, greenlet, charset-normalizer, certifi, attrs, async-timeout, aiosignal, tenacity, SQLAlchemy, requests, PyYAML, openapi-schema-pydantic, numexpr, dataclasses-json, aiohttp, langchain
Successfully installed PyYAML-6.0 SQLAlchemy-2.0.15 aiohttp-3.8.4 aiosignal-1.3.1 async-timeout-4.0.2 attrs-23.1.0 certifi-2023.5.7 charset-normalizer-3.1.0 dataclasses-json-0.5.7 frozenlist-1.3.3 greenlet-2.0.2 idna-3.4 langchain-0.0.177 marshmallow-3.19.0 marshmallow-enum-1.5.1 multidict-6.0.4 mypy-extensions-1.0.0 numexpr-2.8.4 numpy-1.24.3 openapi-schema-pydantic-1.2.4 packaging-23.1 pydantic-1.10.7 requests-2.31.0 tenacity-8.2.2 typing-extensions-4.6.0 typing-inspect-0.8.0 urllib3-2.0.2 yarl-1.9.2

Who can help?

@hwchase17 @agola11

Information

The official example notebooks/scripts
My own modified scripts

Related Components

LLMs/Chat Models
Embedding Models
Prompts / Prompt Templates / Prompt Selectors
Output Parsers
Document Loaders
Vector Stores / Retrievers
Memory
Agents / Agent Executors
Tools / Toolkits
Chains
Callbacks/Tracing
Async

Reproduction

install python==3.9.7 or 3.9.8 or 3.9.9 (with asdf or docker. I didn’t checked the other versions.)
install langchain pip install langchain
see the error

Python 3.9.7 (default, May 23 2023, 11:05:54) 
[GCC 9.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import langchain
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/takumi/.asdf/installs/python/3.9.7/lib/python3.9/site-packages/langchain/__init__.py", line 6, in <module>
    from langchain.agents import MRKLChain, ReActChain, SelfAskWithSearchChain
  File "/home/takumi/.asdf/installs/python/3.9.7/lib/python3.9/site-packages/langchain/agents/__init__.py", line 2, in <module>
    from langchain.agents.agent import (
  File "/home/takumi/.asdf/installs/python/3.9.7/lib/python3.9/site-packages/langchain/agents/agent.py", line 16, in <module>
    from langchain.agents.tools import InvalidTool
  File "/home/takumi/.asdf/installs/python/3.9.7/lib/python3.9/site-packages/langchain/agents/tools.py", line 8, in <module>
    from langchain.tools.base import BaseTool, Tool, tool
  File "/home/takumi/.asdf/installs/python/3.9.7/lib/python3.9/site-packages/langchain/tools/__init__.py", line 42, in <module>
    from langchain.tools.vectorstore.tool import (
  File "/home/takumi/.asdf/installs/python/3.9.7/lib/python3.9/site-packages/langchain/tools/vectorstore/tool.py", line 13, in <module>
    from langchain.chains import RetrievalQA, RetrievalQAWithSourcesChain
  File "/home/takumi/.asdf/installs/python/3.9.7/lib/python3.9/site-packages/langchain/chains/__init__.py", line 2, in <module>
    from langchain.chains.api.base import APIChain
  File "/home/takumi/.asdf/installs/python/3.9.7/lib/python3.9/site-packages/langchain/chains/api/base.py", line 13, in <module>
    from langchain.chains.api.prompt import API_RESPONSE_PROMPT, API_URL_PROMPT
  File "/home/takumi/.asdf/installs/python/3.9.7/lib/python3.9/site-packages/langchain/chains/api/prompt.py", line 2, in <module>
    from langchain.prompts.prompt import PromptTemplate
  File "/home/takumi/.asdf/installs/python/3.9.7/lib/python3.9/site-packages/langchain/prompts/__init__.py", line 3, in <module>
    from langchain.prompts.chat import (
  File "/home/takumi/.asdf/installs/python/3.9.7/lib/python3.9/site-packages/langchain/prompts/chat.py", line 10, in <module>
    from langchain.memory.buffer import get_buffer_string
  File "/home/takumi/.asdf/installs/python/3.9.7/lib/python3.9/site-packages/langchain/memory/__init__.py", line 28, in <module>
    from langchain.memory.vectorstore import VectorStoreRetrieverMemory
  File "/home/takumi/.asdf/installs/python/3.9.7/lib/python3.9/site-packages/langchain/memory/vectorstore.py", line 10, in <module>
    from langchain.vectorstores.base import VectorStoreRetriever
  File "/home/takumi/.asdf/installs/python/3.9.7/lib/python3.9/site-packages/langchain/vectorstores/__init__.py", line 2, in <module>
    from langchain.vectorstores.analyticdb import AnalyticDB
  File "/home/takumi/.asdf/installs/python/3.9.7/lib/python3.9/site-packages/langchain/vectorstores/analyticdb.py", line 16, in <module>
    from langchain.embeddings.base import Embeddings
  File "/home/takumi/.asdf/installs/python/3.9.7/lib/python3.9/site-packages/langchain/embeddings/__init__.py", line 19, in <module>
    from langchain.embeddings.openai import OpenAIEmbeddings
  File "/home/takumi/.asdf/installs/python/3.9.7/lib/python3.9/site-packages/langchain/embeddings/openai.py", line 67, in <module>
    class OpenAIEmbeddings(BaseModel, Embeddings):
  File "pydantic/main.py", line 197, in pydantic.main.ModelMetaclass.__new__
  File "pydantic/fields.py", line 506, in pydantic.fields.ModelField.infer
  File "pydantic/fields.py", line 436, in pydantic.fields.ModelField.__init__
  File "pydantic/fields.py", line 552, in pydantic.fields.ModelField.prepare
  File "pydantic/fields.py", line 663, in pydantic.fields.ModelField._type_analysis
  File "pydantic/fields.py", line 808, in pydantic.fields.ModelField._create_sub_type
  File "pydantic/fields.py", line 436, in pydantic.fields.ModelField.__init__
  File "pydantic/fields.py", line 552, in pydantic.fields.ModelField.prepare
  File "pydantic/fields.py", line 668, in pydantic.fields.ModelField._type_analysis
  File "/home/takumi/.asdf/installs/python/3.9.7/lib/python3.9/typing.py", line 847, in __subclasscheck__
    return issubclass(cls, self.__origin__)
TypeError: issubclass() arg 1 must be a class
>>>

with docker

$ docker run -it python:3.9.7-bullseye bash
$ pip install langchain
$ python -c "import langchain"

Expected behavior

Python 3.10.1 (main, Dec 21 2021, 09:01:08) [GCC 10.2.1 20210110] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import langchain
>>>

what to do?
- ~change python dependency to 3.10 or later~
- fix the version of typing_extensions to 4.5.0 or change the relevant code.
Thank you for checking out this issue. If there are anything more to check, I would be glad to help.

About this issue

Original URL
State: closed
Created a year ago
Reactions: 10
Comments: 31 (3 by maintainers)

Commits related to this issue

force typing extension version because of https://github.com/hwchase17/langchain/issues/5113 — committed to Chainlit/chainlit by willydouhard a year ago

Most upvoted comments

Fix version of these dependence:

typing-inspect==0.8.0
typing_extensions==4.5.0

Solve the issue for me:

+39

KhaledLela on May 23, 2023

Fix version of these dependence:
typing-inspect==0.8.0
typing_extensions==4.5.0
Solve the issue for me:

It worked! Thank you!

typing_extensions was updated only a few hours ago and it seems to have caused something. https://pypi.org/project/typing-extensions/#history

+15

tand826 on May 23, 2023

fixed the issue with pydantic==1.10.8

cibernicola on Jul 1, 2023

Thanks !

pip install pydantic==1.10.8 works for me

maxoute on Jun 15, 2023

Fix version of these dependence:
typing-inspect==0.8.0
typing_extensions==4.5.0
Solve the issue for me:

Hmm it’s not working for me. I had tried to uninstall both packages and langchain and then reinstall them as well. Any other pointers?

jpzhangvincent on May 23, 2023

Solve the issue for me: pip install pydantic==1.10.8 works for me Thanks

blakefan on Jul 2, 2023

Running in to this for python v3.8 and v3.9

I suspect some package that has not been pinned has been updated in the past few hours on pypi

iterix on May 23, 2023

can confirm that on my side, running this command fixed the problem pip install typing-inspect==0.8.0 typing_extensions==4.5.0

misirov on May 27, 2023

Latest pydantic==1.10.8 fixed this issue in here. Langchain needs no update because pydantic dependency is > 1 in here.

Just in case, this is how to check the update.

docker run -it --rm python:3.9-bullseye bash
pip install langchain
python -m "import langchain"
pip freeze | grep pydantic

tand826 on May 24, 2023

BTW it also fails with typing_extensions==4.6.0.

Python 3.9.16 (main, Mar  8 2023, 14:00:05)
[GCC 11.2.0] :: Anaconda, Inc. on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from langchain.embeddings import OpenAIEmbeddings
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/adumont/ai/streamlit-confluence/venv/lib/python3.9/site-packages/langchain/__init__.py", line 6, in <module>
    from langchain.agents import MRKLChain, ReActChain, SelfAskWithSearchChain
  File "/home/adumont/ai/streamlit-confluence/venv/lib/python3.9/site-packages/langchain/agents/__init__.py", line 2, in <module>
    from langchain.agents.agent import (
  File "/home/adumont/ai/streamlit-confluence/venv/lib/python3.9/site-packages/langchain/agents/agent.py", line 16, in <module>
    from langchain.agents.tools import InvalidTool
  File "/home/adumont/ai/streamlit-confluence/venv/lib/python3.9/site-packages/langchain/agents/tools.py", line 8, in <module>
    from langchain.tools.base import BaseTool, Tool, tool
  File "/home/adumont/ai/streamlit-confluence/venv/lib/python3.9/site-packages/langchain/tools/__init__.py", line 42, in <module>
    from langchain.tools.vectorstore.tool import (
  File "/home/adumont/ai/streamlit-confluence/venv/lib/python3.9/site-packages/langchain/tools/vectorstore/tool.py", line 13, in <module>
    from langchain.chains import RetrievalQA, RetrievalQAWithSourcesChain
  File "/home/adumont/ai/streamlit-confluence/venv/lib/python3.9/site-packages/langchain/chains/__init__.py", line 2, in <module>
    from langchain.chains.api.base import APIChain
  File "/home/adumont/ai/streamlit-confluence/venv/lib/python3.9/site-packages/langchain/chains/api/base.py", line 13, in <module>
    from langchain.chains.api.prompt import API_RESPONSE_PROMPT, API_URL_PROMPT
  File "/home/adumont/ai/streamlit-confluence/venv/lib/python3.9/site-packages/langchain/chains/api/prompt.py", line 2, in <module>
    from langchain.prompts.prompt import PromptTemplate
  File "/home/adumont/ai/streamlit-confluence/venv/lib/python3.9/site-packages/langchain/prompts/__init__.py", line 3, in <module>
    from langchain.prompts.chat import (
  File "/home/adumont/ai/streamlit-confluence/venv/lib/python3.9/site-packages/langchain/prompts/chat.py", line 10, in <module>
    from langchain.memory.buffer import get_buffer_string
  File "/home/adumont/ai/streamlit-confluence/venv/lib/python3.9/site-packages/langchain/memory/__init__.py", line 28, in <module>
    from langchain.memory.vectorstore import VectorStoreRetrieverMemory
  File "/home/adumont/ai/streamlit-confluence/venv/lib/python3.9/site-packages/langchain/memory/vectorstore.py", line 10, in <module>
    from langchain.vectorstores.base import VectorStoreRetriever
  File "/home/adumont/ai/streamlit-confluence/venv/lib/python3.9/site-packages/langchain/vectorstores/__init__.py", line 2, in <module>
    from langchain.vectorstores.analyticdb import AnalyticDB
  File "/home/adumont/ai/streamlit-confluence/venv/lib/python3.9/site-packages/langchain/vectorstores/analyticdb.py", line 16, in <module>
    from langchain.embeddings.base import Embeddings
  File "/home/adumont/ai/streamlit-confluence/venv/lib/python3.9/site-packages/langchain/embeddings/__init__.py", line 19, in <module>
    from langchain.embeddings.openai import OpenAIEmbeddings
  File "/home/adumont/ai/streamlit-confluence/venv/lib/python3.9/site-packages/langchain/embeddings/openai.py", line 67, in <module>
    class OpenAIEmbeddings(BaseModel, Embeddings):
  File "pydantic/main.py", line 197, in pydantic.main.ModelMetaclass.__new__
  File "pydantic/fields.py", line 506, in pydantic.fields.ModelField.infer
  File "pydantic/fields.py", line 436, in pydantic.fields.ModelField.__init__
  File "pydantic/fields.py", line 552, in pydantic.fields.ModelField.prepare
  File "pydantic/fields.py", line 663, in pydantic.fields.ModelField._type_analysis
  File "pydantic/fields.py", line 808, in pydantic.fields.ModelField._create_sub_type
  File "pydantic/fields.py", line 436, in pydantic.fields.ModelField.__init__
  File "pydantic/fields.py", line 552, in pydantic.fields.ModelField.prepare
  File "pydantic/fields.py", line 668, in pydantic.fields.ModelField._type_analysis
  File "/home/adumont/miniconda3/envs/ai39/lib/python3.9/typing.py", line 852, in __subclasscheck__
    return issubclass(cls, self.__origin__)
TypeError: issubclass() arg 1 must be a class

adumont on May 23, 2023

Fix version of these dependence:
typing-inspect==0.8.0
typing_extensions==4.5.0
Solve the issue for me:
It worked! Thank you!

typing_extensions was updated only a few hours ago and it seems to have caused something. https://pypi.org/project/typing-extensions/#history

TY - I thought I was losing my mind. Was working on my laptop but not my GCP instance. This fixed it.

benwilde on May 23, 2023

Spent hours debugging this. Glad I found this thread. python:3.10-slim worked for me. Thanks @tiensunguyen

maail on May 23, 2023

In Dockerfile, FROM python:3.10-slim is ok for me.

tiensunguyen on May 23, 2023

I encountered the same error while using langchain on Docker.

Here’s my Dockerfile:

FROM python:3.8-slim
# I also tried python:3.8, python:3.8-buster, python:3.9-slim and didn't work.
# pyton:3.10-slim works for me.

I didn’t face this issue on my local Ubuntu as below with python-3.8.

NAME="Ubuntu"
VERSION="20.04.6 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04.6 LTS"
VERSION_ID="20.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=focal
UBUNTU_CODENAME=focal

I modified requirements.txt by changing langchain==0.0.173 to langchain==0.0.125, and it worked.

$ sudo docker-compose run web bash
root@5bf0c69be9ec:/app# python --version
Python 3.8.16
root@5bf0c69be9ec:/app# python
Python 3.8.16 (default, May  3 2023, 10:09:08) 
[GCC 10.2.1 20210110] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import langchain
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.8/site-packages/langchain/__init__.py", line 6, in <module>
    from langchain.agents import MRKLChain, ReActChain, SelfAskWithSearchChain
  File "/usr/local/lib/python3.8/site-packages/langchain/agents/__init__.py", line 2, in <module>
    from langchain.agents.agent import (
  File "/usr/local/lib/python3.8/site-packages/langchain/agents/agent.py", line 16, in <module>
    from langchain.agents.tools import InvalidTool
  File "/usr/local/lib/python3.8/site-packages/langchain/agents/tools.py", line 8, in <module>
    from langchain.tools.base import BaseTool, Tool, tool
  File "/usr/local/lib/python3.8/site-packages/langchain/tools/__init__.py", line 42, in <module>
    from langchain.tools.vectorstore.tool import (
  File "/usr/local/lib/python3.8/site-packages/langchain/tools/vectorstore/tool.py", line 13, in <module>
    from langchain.chains import RetrievalQA, RetrievalQAWithSourcesChain
  File "/usr/local/lib/python3.8/site-packages/langchain/chains/__init__.py", line 2, in <module>
    from langchain.chains.api.base import APIChain
  File "/usr/local/lib/python3.8/site-packages/langchain/chains/api/base.py", line 13, in <module>
    from langchain.chains.api.prompt import API_RESPONSE_PROMPT, API_URL_PROMPT
  File "/usr/local/lib/python3.8/site-packages/langchain/chains/api/prompt.py", line 2, in <module>
    from langchain.prompts.prompt import PromptTemplate
  File "/usr/local/lib/python3.8/site-packages/langchain/prompts/__init__.py", line 3, in <module>
    from langchain.prompts.chat import (
  File "/usr/local/lib/python3.8/site-packages/langchain/prompts/chat.py", line 10, in <module>
    from langchain.memory.buffer import get_buffer_string
  File "/usr/local/lib/python3.8/site-packages/langchain/memory/__init__.py", line 28, in <module>
    from langchain.memory.vectorstore import VectorStoreRetrieverMemory
  File "/usr/local/lib/python3.8/site-packages/langchain/memory/vectorstore.py", line 10, in <module>
    from langchain.vectorstores.base import VectorStoreRetriever
  File "/usr/local/lib/python3.8/site-packages/langchain/vectorstores/__init__.py", line 2, in <module>
    from langchain.vectorstores.analyticdb import AnalyticDB
  File "/usr/local/lib/python3.8/site-packages/langchain/vectorstores/analyticdb.py", line 15, in <module>
    from langchain.embeddings.base import Embeddings
  File "/usr/local/lib/python3.8/site-packages/langchain/embeddings/__init__.py", line 19, in <module>
    from langchain.embeddings.openai import OpenAIEmbeddings
  File "/usr/local/lib/python3.8/site-packages/langchain/embeddings/openai.py", line 67, in <module>
    class OpenAIEmbeddings(BaseModel, Embeddings):
  File "pydantic/main.py", line 197, in pydantic.main.ModelMetaclass.__new__
  File "pydantic/fields.py", line 506, in pydantic.fields.ModelField.infer
  File "pydantic/fields.py", line 436, in pydantic.fields.ModelField.__init__
  File "pydantic/fields.py", line 552, in pydantic.fields.ModelField.prepare
  File "pydantic/fields.py", line 663, in pydantic.fields.ModelField._type_analysis
  File "pydantic/fields.py", line 808, in pydantic.fields.ModelField._create_sub_type
  File "pydantic/fields.py", line 436, in pydantic.fields.ModelField.__init__
  File "pydantic/fields.py", line 552, in pydantic.fields.ModelField.prepare
  File "pydantic/fields.py", line 668, in pydantic.fields.ModelField._type_analysis
  File "/usr/local/lib/python3.8/typing.py", line 774, in __subclasscheck__
    return issubclass(cls, self.__origin__)
TypeError: issubclass() arg 1 must be a class
>>>

sts-kanada on May 23, 2023

The pypi says ">Python >=3.8.1, <4.0 " https://pypi.org/project/langchain/#description

nai-kon on May 23, 2023

I get the same error on py3.9 too. and on Python 3.10.6, it is ok.

Liweixin22 on May 23, 2023