Day 36: Misusing Decorators

 

🐍 Python Mistakes Everyone Makes ❌

Day 36: Misusing Decorators

Decorators are powerful—but easy to misuse. A small mistake can change function behavior or break it silently.

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❌ The Mistake

Forgetting to return the wrapped function’s result.

def my_decorator(func):
    def wrapper(*args, **kwargs):
        print("Before function")
        func(*args, **kwargs) # ❌ return missing
        print("After function")

return wrapper

@my_decorator
def greet():
  return "Hello"

print(greet()) # None 😕

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❌ Why This Fails

• The wrapper does not return the function’s result

• The original return value is lost

• Function behavior changes unexpectedly

• No error is raised — silent bug

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✅ The Correct Way

def my_decorator(func): 
def wrapper(*args, **kwargs):
        print("Before function")
  result = func(*args, **kwargs)
     print("After function") 
     return result 
return wrapper 

@my_decorator
def greet():
     return "Hello"

print(greet()) # Hello ✅

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✔ Another Common Decorator Mistake

Not preserving metadata:

from functools import wraps

def my_decorator(func):
  @wraps(func)
   def wrapper(*args, **kwargs):
       return func(*args, **kwargs) 

return wrapper

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🧠 Simple Rule to Remember

🐍 Always return the wrapped function’s result
🐍 Use functools.wraps
🐍 Test decorators carefully

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Decorators are powerful handle them with care 🚀