DeepSeek API: Complete Python Integration Guide

Category: AI Coding Difficulty: Intermediate Updated: 2026-05-28

Complete guide to integrating DeepSeek API in Python. Learn authentication, chat completions, streaming, structured outputs, and pricing optimization.

OpenAI-Compatible API

DeepSeek's API is fully compatible with the OpenAI SDK. You can switch from OpenAI to DeepSeek by changing just the base URL and API key. This means all your existing code works with minimal changes.

Quick Start

pip install openai
from openai import OpenAI

client = OpenAI(
    api_key="your-deepseek-api-key",
    base_url="https://api.deepseek.com"
)

response = client.chat.completions.create(
    model="deepseek-chat",
    messages=[
        {"role": "system", "content": "You are a helpful coding assistant."},
        {"role": "user", "content": "Write a Python function to merge two sorted lists."}
    ],
    stream=False
)

print(response.choices[0].message.content)

Using Deep Think (R1) via API

response = client.chat.completions.create(
    model="deepseek-reasoner",  # Enables Deep Think mode
    messages=[{"role": "user", "content": "Solve this complex algorithm problem..."}]
)

# You can access the reasoning trace:
print("Reasoning:", response.choices[0].message.reasoning_content)
print("Answer:", response.choices[0].message.content)

Pricing Optimization Tips