Python Coding Challange - Question with Answer (01270925)

 

🔎 Step 1: What is __globals__?

• Every function in Python has a __globals__ attribute.

• It’s a dictionary containing the global namespace where the function was defined.

• That dictionary also contains a key called "__builtins__".

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🔎 Step 2: What is __builtins__?

• "__builtins__" points to Python’s built-in functions and objects.

• Depending on the environment:

  • Sometimes it’s a dictionary of builtins.

  • Sometimes it’s the builtins module.

So here:

add.__globals__['__builtins__']

👉 is the builtins module.

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🔎 Step 3: Accessing sum

add.__globals__['__builtins__'].sum

👉 fetches the sum function from the builtins module.

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🔎 Step 4: What is range(3)?

range(3) → [0, 1, 2] # when iterated

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🔎 Step 5: Calling it

sum(range(3)) = 0 + 1 + 2 = 3

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✅ Final Output:

3

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⚡ Why not just sum(range(3))?

• Normally, you’d just use sum(range(3)).

• Using add.__globals__['__builtins__'].sum is a deep lookup:

  • function → global namespace → builtins module → sum function.

• It shows that Python lets you reach built-in functions through namespaces manually.

Probability and Statistics using Python