level1 → part2 full code

🤫 Loading Environment Variables

import os
from dotenv import load_dotenv

load_dotenv(override=True)
api_key = os.getenv('OPENAI_API_KEY')

if not api_key:
    print("No API key was found - please head over to the troubleshooting notebook in this folder to identify & fix!")
elif not api_key.startswith("sk-proj-"):
    print("An API key was found, but it doesn't start sk-proj-; please check you're using the right key - see troubleshooting notebook")
else:
    print("API key found and looks good so far!")

☎️ Endpoint Payload Setup and Calling API

Payload and Header

import requests

headers = {"Authorization": f"Bearer {api_key}", "Content-Type": "application/json"}

payload = {
    "model": "gpt-5-nano",
    "messages": [
        {"role": "user", "content": "Tell me a fun fact"}]
}

payload ## prints the payload

Calling the Endpoint

response = requests.post(
    "<https://api.openai.com/v1/chat/completions>",
    headers=headers,
    json=payload
)

response.json() ## prints the response

Print Relevant Message

response.json()["choices"][0]["message"]["content"]

🧐 Client Library vs API

API Approach

import requests

headers = {
    "Content-Type": "application/json",
    "Authorization": f"Bearer {os.getenv('OPENAI_API_KEY')}"
}
payload = {
    "model": "gpt-5-nano",
    "messages": [{"role": "user", "content": "Tell me a fun fact"}]
}
response = requests.post(
    "<https://api.openai.com/v1/chat/completions>",
    headers=headers,
    json=payload
)
print(response.json()["choices"][0]["message"]["content"])

Client Library Approach

from openai import OpenAI

client = OpenAI()
response = client.chat.completions.create(
    model="gpt-5-nano",
    messages=[{"role": "user", "content": "Tell me a fun fact"}]
)
print(response.choices[0].message.content)

🧪 Try Google Gemini

GEMINI_BASE_URL = "<https://generativelanguage.googleapis.com/v1beta/openai/>"

load_dotenv(override=True)

google_api_key = os.getenv("GOOGLE_API_KEY")

if not google_api_key:
    print("No API key was found - please be sure to add your key to the .env file, and save the file! Or you can skip the next 2 cells if you don't want to use Gemini")
elif not google_api_key.startswith("AIz"):
    print("An API key was found, but it doesn't start AIz")
else:
    print("API key found and looks good so far!")

gemini = OpenAI(base_url=GEMINI_BASE_URL, api_key=google_api_key)

response = gemini.chat.completions.create(model="gemini-2.5-flash-lite", messages=[{"role": "user", "content": "Tell me a fun fact"}])

response.choices[0].message.content

🧪 Try Ollama

requests.get("<http://localhost:11434>").content 
## check ollama is running or not

!ollama serve ## in case ollama not running

!ollama pull llama3.2

OLLAMA_BASE_URL = "<http://localhost:11434/v1>"

ollama = OpenAI(base_url=OLLAMA_BASE_URL, api_key='ollama')

response = ollama.chat.completions.create(
    model="llama3.2",
    messages=[{"role": "user", "content": "Tell me a fun fact"}]
)
print(response.choices[0].message.content)

🧪 Try DeepSeek R1

!ollama pull deepseek-r1:1.5b ## pull deepseek model

response = ollama.chat.completions.create(
    model="deepseek-r1:1.5b",
    messages=[{"role": "user", "content": "Tell me a fun fact"}]
)
print(response.choices[0].message.content)