Day 10: Assuming 0, "", [] are errors

 

🐍Python Mistakes Everyone Makes ❌

Day 10: Assuming 0, "", and [] are Errors

One common Python mistake is treating empty or zero values as errors.

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❌ The Mistake

x = 0

if not x:
    print("Error occurred")

At first glance, this looks fine. But it’s misleading.

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✅ The Correct Way

x = 0

if x is None:
      print("Error occurred")
else:
   print("Valid value")

❌ Why This Fails?

Because 0, "", and [] are valid values, not errors.
Using if not x: only checks emptiness, not whether something actually went wrong.

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✔ What if not x Really Means

• It checks if a value is falsy

• It does not mean an error occurred

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🧠 Simple Rule to Remember

Falsy values in Python:

1.  0

2.""(empty string)

3.[](empty list)

4.{}(empty dict)

5.None

6.False 

Falsy ≠ Error

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🔑 Key Takeaway

Use is None when checking for missing or invalid data.
Use if not x only when you truly mean empty.