# 3.1 환경 설정과 LangChain의 ChatOpenAI를 활용한 검증

* 파이썬 가상환경 설정
  * [conda](https://conda.io/projects/conda/en/latest/user-guide/getting-started.html) ↗️, [virtualenv](https://virtualenv.pypa.io/en/latest/) ↗️ 등 이미 사용중인 방법이 있다면 해당 방법 사용
  * 개인적으로 [pyenv](https://github.com/pyenv/pyenv) ↗️ 추천
* 환경변수 관리
  * [python-dotenv](https://pypi.org/project/python-dotenv/) ↗️  활용
  * `load_dotenv()` 를 활용하면 `.env` 의 값을 불러올 수 있음
* 이번 강의의 목적은 [ChatOpenAI](https://python.langchain.com/v0.2/docs/integrations/chat/openai/) ↗️ 를 활용해서 LLM의 답변을 생성하는 것
  * 환경변수를 `ChatOpenAI` 에 매번 넣어주지 않으려면 OpenAI Dashboard에서 생성한 API KEY를 `OPENAI_API_KEY` 라는 이름으로 저장해야함
  * quota 초과 에러메시지가 나온다면 [OpenAI Dashboard](https://platform.openai.com/settings/organization/billing/overview) ↗️ 에 들어가셔서 `Credit Balance` 를 확인해주세요

<figure><img src="/files/o9Suc2TCvSEt7mWYBHah" alt=""><figcaption></figcaption></figure>


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