Day 19:Using global variables unnecessarily

 

🐍 Python Mistakes Everyone Makes ❌

🐍 Day 19: Using Global Variables Unnecessarily

Global variables may look convenient, but they often create more problems than they solve—especially as your code grows.

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❌ The Mistake

count = 0

def increment():
    global count 
    count += 1

This function depends on a global variable and modifies it directly.

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❌ Why This Is a Problem

Using globals:

• Makes code harder to debug

• Causes unexpected side effects

• Breaks function reusability

• Couples logic tightly to external state

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✅ The Correct Way

def increment(count):
     return count + 1 

count = increment(count)

Now the function is predictable, testable, and reusable.

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✔ Why This Is Better

✔ Functions depend only on inputs
✔ No hidden state
✔ Easier to test and debug
✔ Cleaner design

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🧠 Simple Rule to Remember

🐍 Functions should depend on arguments, not globals
🐍 Pass data in, return data out