Debugging : Why not pprint anymore? Introducing SetPrint: Structural Debugging for Real Data

When your data grows beyond a toy example, pprint starts to break.

You see cut-off arrays. Flattened hierarchies. Lost context.

And worst of all? Hidden bugs buried under “pretty” formatting.

That’s why I created SetPrint — a Python library that shows structure, not just values.

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🔍 What this article covers

• ✅ Side-by-side comparisons: pprint / setprint
• ✅ Real-world examples: image data, confusion matrices
• ✅ Benchmarks + 5 must-know tips for structured debugging

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🧪 Quick Colab Demo

Want to see it in action? Try this demo notebook — no install needed.

(To use Colab, a Google account is required.)

🔗 Try this notebook on Google Colab

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1. Visual Comparison — pprint vs setprint

data = {
    "users": [
        {"name": "Alice", "scores": np.array([95, 88, 76])},
        {"name": "Bob",   "scores": np.array([72, 85, 90])}
    ],
    "meta": {"created": "2025-04-23", "version": 1.2}
}

== pprint ==
{'meta': {'created': '2025-04-23', 'version': 1.2},
 'users': [{'name': 'Alice', 'scores': array([95, 88, 76])},
           {'name': 'Bob', 'scores': array([72, 85, 90])}]}

== setprint ==
keep_settings
['y', 'y', 'y', 'y']
--------------------------------------------------------

◆dict 
  ├── users:►list 
  │        ├───── -------.  ◆dict    
  │        │              ├─────────  name : Alice   
  │        │              └───────── scores:>ndarray 
  │        │                                ├─────── 95 
  │        │                                ├─────── 88 
  │        │                                └─────── 76 
  │        └───── -------.  ◆dict    
  │                       ├─────────  name :  Bob    
  │                       └───────── scores:>ndarray 
  │                                         ├─────── 72 
  │                                         ├─────── 85 
  │                                         └─────── 90 
  └── meta :◆dict 
           ├───── created:2025-04-23 
           └───── version:   1.2     

--------------------------------------------------------

Even at a glance, the structure is crystal clear.

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2. Image Arrays? No Problem

rgb = np.random.randint(0, 255, size=(3, 3, 3))
set_collection ( route='SLIM', y_axis=False, keep_settings={1: 'yf', 2: 'f'} )

keep_settings
['yf', 'f', 'f']
-------------------------------------------------------------------------------------------------

>ndarray 
   ├──── >ndarray [ >ndarray [ 255  0   4  ] >ndarray [ 255 85   0  ] >ndarray [ 255 170  0  ] ] 
   ├──── >ndarray [ >ndarray [ 170 255  0  ] >ndarray [ 85  255  0  ] >ndarray [  0  255  4  ] ] 
   └──── >ndarray [ >ndarray [  0  170 255 ] >ndarray [  0  85  255 ] >ndarray [  4   0  255 ] ] 

-------------------------------------------------------------------------------------------------

You don’t just see the values—you see the hierarchy.

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3. Confusion Matrices as Text-Based Heatmaps

cm = np.array([[50, 2, 0, 0], [3, 45, 1, 0], [0, 4, 60, 5], [0, 0, 6, 70]])
set_collection ( route='SLIM', y_axis=False, keep_settings={1:'y', 2:'x'} )

keep_settings
['y', 'x']
------------------------------

>ndarray 
   ├──── >ndarray ┬──┬──┬──┐
   │              50 2  0  0  
   ├──── >ndarray ┬──┬──┬──┐
   │              3  45 1  0  
   ├──── >ndarray ┬──┬──┬──┐
   │              0  4  60 5  
   └──── >ndarray ┬──┬──┬──┐
                  0  0  6  70 

------------------------------

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4. Benchmark: Visibility vs Speed

Library	Runtime (ms)	Structure Clarity
pprint	1.5	★☆☆☆☆
rich.pretty	3.2	★★☆☆☆
setprint	4.8	★★★★★

A few ms extra for full visibility? Totally worth it.

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5. 5 Must-Know Tips for Using SetPrint

1. Use keep_settings = {1: 'x', 3: 'yf', 4: 'f'} for full control over dimensions
2. Show vertical guides with y_axis=True
3. Output is a list of lines → easy to write to file
4. Handles mixed types: dict + list + ndarray? No problem
5. Switch between styles like 'SLIM', 'BOLD', or even 'HALF'

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6. One Function, Infinite Views

from setprint import SetPrint
list_data = SetPrint(data)

formatted = list_data.set_collection(
    keep_settings={1:'x', 2:'yf', 3:'f'},
    route='SLIM', y_axis=True
)

for line in formatted:
    print(line)

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🚀 Try it Now

pip install setprint

🎯 If you found it useful, please consider giving a ⭐ on GitHub!
🐛 Bug reports, 💡 feature requests, and 📬 pull requests are all welcome!

📎 GitHub: mtur2007/SetPrint

📘 PyPI: setprint

🔍 Colab Demo: Try on Colab

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🔗 Also available on Medium!

💬 I'd love to hear your feedback on either platform. ✨

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If you’ve ever said “I just want to see the damn structure” — SetPrint is for you.

(Thank you for reading! This is my very first article introducing SetPrint to the international audience. I'd love to hear your feedback and thoughts.)