# Code Smell 305 - Null Infinity > TL;DR: Use *Infinity* instead of *None* when looking for minimums # Problems πŸ˜” - [Accidental IFs](https://maximilianocontieri.com/how-to-get-rid-of-annoying-ifs-forever) - Wrong default - Bad [polymorphism](https://maximilianocontieri.com/code-smell-102-arrow-code) - Extra conditions - Hidden initialization - Wrong domain mapping - Misleading behavior - Unnecessary conditionals - Complex logic - [Null checks](https://maximilianocontieri.com/code-smell-12-null) - Error-prone code # Solutions πŸ˜ƒ 1. Remove the [Accidental IFs](https://maximilianocontieri.com/refactoring-014-remove-if) 2. Use *infinite value* 3. Remove *None check* 4. Respect [math semantics](https://maximilianocontieri.com/the-one-and-only-software-design-principle) and consistency 5. Apply the [null object](https://maximilianocontieri.com/refactoring-015-remove-null) pattern 6. Reduce boilerplate, simplifying your code 7. Use float('inf') as base case for minimums ♾️ 8. Use float('-inf') as base case for maximums -♾️ 9. Remove conditional branches # Refactorings βš™οΈ %[https://maximilianocontieri.com/refactoring-014-remove-if] %[https://maximilianocontieri.com/refactoring-015-remove-null] # Context πŸ’¬ ## Problem 1: You want to find the greatest number in a list. You start with 0 and compare. An amazing [Null Object](https://maximilianocontieri.com/null-the-billion-dollar-mistake). No Accidental IFs involved. Clean code. πŸ‘Œ ## Problem 2: You want to find the lowest number in a list. Most beginners start with *None* and check "if current is *None* or x < current". You don’t need that. You can start with *float("inf")* ♾️. It [behaves-as-a](https://maximilianocontieri.com/code-smell-125-is-a-relationship) a number. You can compare, sort, and minimize it. This gives you simpler logic and polymorphic code. The holy grail of behavior. # Sample Code πŸ“– ## Wrong ❌ ```python def find_minimum_price(products): min_price = None for product in products: if min_price is None: min_price = product.price elif product.price < min_price: min_price = product.price return min_price def find_minimum_in_list(numbers): if not numbers: return None minimum = None for number in numbers: if minimum is None or number < minimum: minimum = number return minimum # Usage leads to more None checks prices = [10.5, 8.2, 15.0, 7.8] min_price = find_minimum_in_list(prices) if min_price is not None: print(f"Minimum price: ${min_price}") else: print("No prices found") ``` ## Right πŸ‘‰ ```python def find_minimum_price(products): min_price = float('inf') for product in products: if product.price < min_price: # This is an essential IF, you should not remove it min_price = product.price # No accidental IF here (if min_price is None:) return min_price if min_price != float('inf') else None def find_minimum_in_list(numbers): minimum = float('inf') for number in numbers: if number < minimum: minimum = number return minimum if minimum != float('inf') else None # Cleaner usage - polymorphic behavior prices = [10.5, 8.2, 15.0, 7.8] min_price = find_minimum_in_list(prices) print(f"Minimum price: ${min_price}") ``` # Detection πŸ” [X] Semi-Automatic You can grep your codebase for *None* inside loops. If you check against *None* before comparing values, you probably smell it. Look for if current is None or x < current. # Tags 🏷️ - Null # Level πŸ”‹ [X] Beginner # Why the Bijection Is Important πŸ—ΊοΈ In math, the identity element for finding a minimum is positive infinity. ♾️ When you use *None*, you break the [MAPPER](https://maximilianocontieri.com/what-is-wrong-with-software) None **is not** a number. It does not behave as a number; it is not polymorphic with numbers. it is evil *Null* disguised as *None. You must then write special code to treat it. That breaks the [bijection](https://maximilianocontieri.com/the-one-and-only-software-design-principle) between your code and math. When you use float("inf"), you stay close to the real concept. The code models the domain truthfully. # AI Generation πŸ€– AI models that generate loops often use *None* as the starting point. They may include unnecessary checks. This typically occurs when the model attempts to mimic tutorials or is trained with bad code or overly simplified examples. # AI Detection 🧲 AI can easily detect and fix this issue when you provide clear instructions. For example > Use *Infinity* for minimum search initialization or > Apply the null object pattern for mathematical operations. ## Try Them! πŸ›  *Remember: AI Assistants make lots of mistakes* > Suggested Prompt: Use Infinity for minimum search initialization | Without Proper Instructions | With Specific Instructions | | -------- | ------- | | [ChatGPT](https://chat.openai.com/?q=Correct+and+explain+this+code%3A+%60%60%60python%0D%0Adef+find_minimum_price%28products%29%3A%0D%0A++++min_price+%3D+None%0D%0A++++%0D%0A++++for+product+in+products%3A%0D%0A++++++++if+min_price+is+None%3A%0D%0A++++++++++++min_price+%3D+product.price%0D%0A++++++++elif+product.price+%3C+min_price%3A%0D%0A++++++++++++min_price+%3D+product.price%0D%0A++++%0D%0A++++return+min_price%0D%0A%0D%0Adef+find_minimum_in_list%28numbers%29%3A%0D%0A++++if+not+numbers%3A%0D%0A++++++++return+None%0D%0A++++%0D%0A++++minimum+%3D+None%0D%0A++++for+number+in+numbers%3A%0D%0A++++++++if+minimum+is+None+or+number+%3C+minimum%3A%0D%0A++++++++++++minimum+%3D+number%0D%0A++++%0D%0A++++return+minimum%0D%0A%0D%0A%23+Usage+leads+to+more+None+checks%0D%0Aprices+%3D+%5B10.5%2C+8.2%2C+15.0%2C+7.8%5D%0D%0Amin_price+%3D+find_minimum_in_list%28prices%29%0D%0Aif+min_price+is+not+None%3A%0D%0A++++print%28f%22Minimum+price%3A+%24%7Bmin_price%7D%22%29%0D%0Aelse%3A%0D%0A++++print%28%22No+prices+found%22%29%0D%0A%60%60%60) 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[ChatGPT](https://chat.openai.com/?q=Use+Infinity+for+minimum+search+initialization%3A+%60%60%60python%0D%0Adef+find_minimum_price%28products%29%3A%0D%0A++++min_price+%3D+None%0D%0A++++%0D%0A++++for+product+in+products%3A%0D%0A++++++++if+min_price+is+None%3A%0D%0A++++++++++++min_price+%3D+product.price%0D%0A++++++++elif+product.price+%3C+min_price%3A%0D%0A++++++++++++min_price+%3D+product.price%0D%0A++++%0D%0A++++return+min_price%0D%0A%0D%0Adef+find_minimum_in_list%28numbers%29%3A%0D%0A++++if+not+numbers%3A%0D%0A++++++++return+None%0D%0A++++%0D%0A++++minimum+%3D+None%0D%0A++++for+number+in+numbers%3A%0D%0A++++++++if+minimum+is+None+or+number+%3C+minimum%3A%0D%0A++++++++++++minimum+%3D+number%0D%0A++++%0D%0A++++return+minimum%0D%0A%0D%0A%23+Usage+leads+to+more+None+checks%0D%0Aprices+%3D+%5B10.5%2C+8.2%2C+15.0%2C+7.8%5D%0D%0Amin_price+%3D+find_minimum_in_list%28prices%29%0D%0Aif+min_price+is+not+None%3A%0D%0A++++print%28f%22Minimum+price%3A+%24%7Bmin_price%7D%22%29%0D%0Aelse%3A%0D%0A++++print%28%22No+prices+found%22%29%0D%0A%60%60%60) 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[Claude](https://claude.ai/new?q=Correct+and+explain+this+code%3A+%60%60%60python%0D%0Adef+find_minimum_price%28products%29%3A%0D%0A++++min_price+%3D+None%0D%0A++++%0D%0A++++for+product+in+products%3A%0D%0A++++++++if+min_price+is+None%3A%0D%0A++++++++++++min_price+%3D+product.price%0D%0A++++++++elif+product.price+%3C+min_price%3A%0D%0A++++++++++++min_price+%3D+product.price%0D%0A++++%0D%0A++++return+min_price%0D%0A%0D%0Adef+find_minimum_in_list%28numbers%29%3A%0D%0A++++if+not+numbers%3A%0D%0A++++++++return+None%0D%0A++++%0D%0A++++minimum+%3D+None%0D%0A++++for+number+in+numbers%3A%0D%0A++++++++if+minimum+is+None+or+number+%3C+minimum%3A%0D%0A++++++++++++minimum+%3D+number%0D%0A++++%0D%0A++++return+minimum%0D%0A%0D%0A%23+Usage+leads+to+more+None+checks%0D%0Aprices+%3D+%5B10.5%2C+8.2%2C+15.0%2C+7.8%5D%0D%0Amin_price+%3D+find_minimum_in_list%28prices%29%0D%0Aif+min_price+is+not+None%3A%0D%0A++++print%28f%22Minimum+price%3A+%24%7Bmin_price%7D%22%29%0D%0Aelse%3A%0D%0A++++print%28%22No+prices+found%22%29%0D%0A%60%60%60) 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[Claude](https://claude.ai/new?q=Use+Infinity+for+minimum+search+initialization%3A+%60%60%60python%0D%0Adef+find_minimum_price%28products%29%3A%0D%0A++++min_price+%3D+None%0D%0A++++%0D%0A++++for+product+in+products%3A%0D%0A++++++++if+min_price+is+None%3A%0D%0A++++++++++++min_price+%3D+product.price%0D%0A++++++++elif+product.price+%3C+min_price%3A%0D%0A++++++++++++min_price+%3D+product.price%0D%0A++++%0D%0A++++return+min_price%0D%0A%0D%0Adef+find_minimum_in_list%28numbers%29%3A%0D%0A++++if+not+numbers%3A%0D%0A++++++++return+None%0D%0A++++%0D%0A++++minimum+%3D+None%0D%0A++++for+number+in+numbers%3A%0D%0A++++++++if+minimum+is+None+or+number+%3C+minimum%3A%0D%0A++++++++++++minimum+%3D+number%0D%0A++++%0D%0A++++return+minimum%0D%0A%0D%0A%23+Usage+leads+to+more+None+checks%0D%0Aprices+%3D+%5B10.5%2C+8.2%2C+15.0%2C+7.8%5D%0D%0Amin_price+%3D+find_minimum_in_list%28prices%29%0D%0Aif+min_price+is+not+None%3A%0D%0A++++print%28f%22Minimum+price%3A+%24%7Bmin_price%7D%22%29%0D%0Aelse%3A%0D%0A++++print%28%22No+prices+found%22%29%0D%0A%60%60%60) 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[Perplexity](https://www.perplexity.ai/?q=Correct+and+explain+this+code%3A+%60%60%60python%0D%0Adef+find_minimum_price%28products%29%3A%0D%0A++++min_price+%3D+None%0D%0A++++%0D%0A++++for+product+in+products%3A%0D%0A++++++++if+min_price+is+None%3A%0D%0A++++++++++++min_price+%3D+product.price%0D%0A++++++++elif+product.price+%3C+min_price%3A%0D%0A++++++++++++min_price+%3D+product.price%0D%0A++++%0D%0A++++return+min_price%0D%0A%0D%0Adef+find_minimum_in_list%28numbers%29%3A%0D%0A++++if+not+numbers%3A%0D%0A++++++++return+None%0D%0A++++%0D%0A++++minimum+%3D+None%0D%0A++++for+number+in+numbers%3A%0D%0A++++++++if+minimum+is+None+or+number+%3C+minimum%3A%0D%0A++++++++++++minimum+%3D+number%0D%0A++++%0D%0A++++return+minimum%0D%0A%0D%0A%23+Usage+leads+to+more+None+checks%0D%0Aprices+%3D+%5B10.5%2C+8.2%2C+15.0%2C+7.8%5D%0D%0Amin_price+%3D+find_minimum_in_list%28prices%29%0D%0Aif+min_price+is+not+None%3A%0D%0A++++print%28f%22Minimum+price%3A+%24%7Bmin_price%7D%22%29%0D%0Aelse%3A%0D%0A++++print%28%22No+prices+found%22%29%0D%0A%60%60%60) 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[Perplexity](https://www.perplexity.ai/?q=Use+Infinity+for+minimum+search+initialization%3A+%60%60%60python%0D%0Adef+find_minimum_price%28products%29%3A%0D%0A++++min_price+%3D+None%0D%0A++++%0D%0A++++for+product+in+products%3A%0D%0A++++++++if+min_price+is+None%3A%0D%0A++++++++++++min_price+%3D+product.price%0D%0A++++++++elif+product.price+%3C+min_price%3A%0D%0A++++++++++++min_price+%3D+product.price%0D%0A++++%0D%0A++++return+min_price%0D%0A%0D%0Adef+find_minimum_in_list%28numbers%29%3A%0D%0A++++if+not+numbers%3A%0D%0A++++++++return+None%0D%0A++++%0D%0A++++minimum+%3D+None%0D%0A++++for+number+in+numbers%3A%0D%0A++++++++if+minimum+is+None+or+number+%3C+minimum%3A%0D%0A++++++++++++minimum+%3D+number%0D%0A++++%0D%0A++++return+minimum%0D%0A%0D%0A%23+Usage+leads+to+more+None+checks%0D%0Aprices+%3D+%5B10.5%2C+8.2%2C+15.0%2C+7.8%5D%0D%0Amin_price+%3D+find_minimum_in_list%28prices%29%0D%0Aif+min_price+is+not+None%3A%0D%0A++++print%28f%22Minimum+price%3A+%24%7Bmin_price%7D%22%29%0D%0Aelse%3A%0D%0A++++print%28%22No+prices+found%22%29%0D%0A%60%60%60) 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[Copilot](https://www.bing.com/chat?showconv=1&sendquery=1&q=Correct+and+explain+this+code%3A+%60%60%60python%0D%0Adef+find_minimum_price%28products%29%3A%0D%0A++++min_price+%3D+None%0D%0A++++%0D%0A++++for+product+in+products%3A%0D%0A++++++++if+min_price+is+None%3A%0D%0A++++++++++++min_price+%3D+product.price%0D%0A++++++++elif+product.price+%3C+min_price%3A%0D%0A++++++++++++min_price+%3D+product.price%0D%0A++++%0D%0A++++return+min_price%0D%0A%0D%0Adef+find_minimum_in_list%28numbers%29%3A%0D%0A++++if+not+numbers%3A%0D%0A++++++++return+None%0D%0A++++%0D%0A++++minimum+%3D+None%0D%0A++++for+number+in+numbers%3A%0D%0A++++++++if+minimum+is+None+or+number+%3C+minimum%3A%0D%0A++++++++++++minimum+%3D+number%0D%0A++++%0D%0A++++return+minimum%0D%0A%0D%0A%23+Usage+leads+to+more+None+checks%0D%0Aprices+%3D+%5B10.5%2C+8.2%2C+15.0%2C+7.8%5D%0D%0Amin_price+%3D+find_minimum_in_list%28prices%29%0D%0Aif+min_price+is+not+None%3A%0D%0A++++print%28f%22Minimum+price%3A+%24%7Bmin_price%7D%22%29%0D%0Aelse%3A%0D%0A++++print%28%22No+prices+found%22%29%0D%0A%60%60%60) 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[Copilot](https://www.bing.com/chat?showconv=1&sendquery=1&q=Use+Infinity+for+minimum+search+initialization%3A+%60%60%60python%0D%0Adef+find_minimum_price%28products%29%3A%0D%0A++++min_price+%3D+None%0D%0A++++%0D%0A++++for+product+in+products%3A%0D%0A++++++++if+min_price+is+None%3A%0D%0A++++++++++++min_price+%3D+product.price%0D%0A++++++++elif+product.price+%3C+min_price%3A%0D%0A++++++++++++min_price+%3D+product.price%0D%0A++++%0D%0A++++return+min_price%0D%0A%0D%0Adef+find_minimum_in_list%28numbers%29%3A%0D%0A++++if+not+numbers%3A%0D%0A++++++++return+None%0D%0A++++%0D%0A++++minimum+%3D+None%0D%0A++++for+number+in+numbers%3A%0D%0A++++++++if+minimum+is+None+or+number+%3C+minimum%3A%0D%0A++++++++++++minimum+%3D+number%0D%0A++++%0D%0A++++return+minimum%0D%0A%0D%0A%23+Usage+leads+to+more+None+checks%0D%0Aprices+%3D+%5B10.5%2C+8.2%2C+15.0%2C+7.8%5D%0D%0Amin_price+%3D+find_minimum_in_list%28prices%29%0D%0Aif+min_price+is+not+None%3A%0D%0A++++print%28f%22Minimum+price%3A+%24%7Bmin_price%7D%22%29%0D%0Aelse%3A%0D%0A++++print%28%22No+prices+found%22%29%0D%0A%60%60%60) | | [Gemini](https://gemini.google.com/) | [Gemini](https://gemini.google.com/) | | [DeepSeek](https://chat.deepseek.com/) | [DeepSeek](https://chat.deepseek.com/) | | [Meta AI](https://www.meta.ai/chat) | [Meta AI](https://www.meta.ai/) | | [Grok](https://grok.com/) | [Grok](https://grok.com/) | | [Qwen](https://chat.qwen.ai/) | [Qwen](https://chat.qwen.ai/) | # Conclusion 🏁 Zero is not the default for everything. When you want to find a minimum, you should start at infinity. This clarifies your code, removes conditionals, and is a better [bijection](https://maximilianocontieri.com/the-one-and-only-software-design-principle) to math. Stop treating *None* like a number. Infinity is polymorphic and is the [the null object for maximum math operations](https://maximilianocontieri.com/code-smell-126-fake-null-object) Use it. # Relations πŸ‘©β€β€οΈβ€πŸ’‹β€πŸ‘¨ %[https://maximilianocontieri.com/code-smell-125-is-a-relationship] %[https://maximilianocontieri.com/code-smell-126-fake-null-object] %[https://maximilianocontieri.com/code-smell-12-null] # More Information πŸ“• %[https://maximilianocontieri.com/how-to-get-rid-of-annoying-ifs-forever] # Disclaimer πŸ“˜ Code Smells are my [opinion](https://maximilianocontieri.com/i-wrote-more-than-90-articles-on-2021-here-is-what-i-learned). # Credits πŸ™ Photo by [Cris Baron](https://unsplash.com/@cris024) on [Unsplash](https://unsplash.com/photos/a-couple-of-people-standing-next-to-each-other-in-the-dark-A18Ub2FbMlE) * * * > Code should model the problem, not the solution _Rich Hickey_ %[https://maximilianocontieri.com/software-engineering-great-quotes] * * * This article is part of the CodeSmell Series. %[https://maximilianocontieri.com/how-to-find-the-stinky-parts-of-your-code]