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Harness the power of OpenAI’s DALL·E 3 to generate stunning visuals from simple text prompts. This step-by-step guide walks you through installation, setup, and examples to help you build your own image generator in Python.

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Table of Contents

  1. Install the OpenAI Python SDK
  2. Initialize the OpenAI Client
  3. Define a Helper Function
  4. Generate Your First Image
  5. Experiment with Custom Prompts
  6. Supported Image Sizes
  7. Links and References

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Install the OpenAI Python SDK

First, install the official OpenAI Python package: 
pip install openai
You can also pin a specific version for reproducibility:
pip install openai==0.27.0

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Initialize the OpenAI Client

Import and initialize the client using your API key. We recommend storing your key in an environment variable for security. 
import os
from openai import OpenAI

api_key = os.getenv("OPENAI_API_KEY")
client = OpenAI(api_key=api_key)
Never hard-code your API key in source files. Use environment variables or a secrets manager.

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Define a Helper Function

Create a reusable function that sends a prompt to DALL·E 3 and returns the URL of the generated image: 
def generate_image(prompt: str, size: str = "1024x1024") -> str:
    """
    Generate an image from a text prompt using DALL·E 3.

    Args:
        prompt: Descriptive text for the image.
        size: One of '256x256', '512x512', or '1024x1024'.

    Returns:
        URL of the generated image.
    """
    response = client.images.generate(
        model="dall-e-3",
        prompt=prompt,
        size=size
    )
    return response.data[0].url

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Generate Your First Image

Use the helper function in a standalone script: 
if __name__ == "__main__":
    prompt = "A person playing golf on Mars with friendly aliens"
    image_url = generate_image(prompt, size="1024x1024")
    print("Generated Image URL:", image_url)
Run it: 
python example.py
# Output:
# Generated Image URL: https://example.com/your-generated-image.png
Open the printed URL in your browser to see your AI-generated artwork.

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Experiment with Custom Prompts

Change the prompt text to explore different styles and concepts: 
if __name__ == "__main__":
    prompt = "A programmer building a robotic dinosaur in a futuristic lab"
    image_url = generate_image(prompt, size="1024x1024")
    print("Generated Image URL:", image_url)
Feel free to iterate on your prompt until you find the perfect visual.

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Supported Image Sizes

SizeDimensionsUse Case
256×256256px by 256pxThumbnails, small icons
512×512512px by 512pxMedium-resolution previews
1024×10241024px by 1024pxHigh-resolution prints or detailed illustrations

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