Simple pipeline to explain the LangChain Expression Language

simple_pipeline.py

from langchain.prompts import ChatPromptTemplate
from langchain.chat_models import ChatOpenAI
from apikey import OPENAI_API_KEY
import os

os.environ['OPENAI_API_KEY'] = OPENAI_API_KEY

model = ChatOpenAI()

prompt = ChatPromptTemplate.from_template("In 2016, who was the president of {country}")

chain = prompt | model

countries = ["United States of America", "France", "Poland", "Cameroon"]

for country in countries:
    response = chain.invoke({"country": country})
    print(response.content)