annotations — Expert Playground

Dictionary of type annotations for a function or class

Python Playground

# __annotations__ internals
import sys

# Inspect how Python stores attributes
class Example:
    class_var = "shared"

    def __init__(self):
        self.instance_var = "unique"

obj = Example()

# Class vs instance namespace
print("Class namespace keys:", list(Example.__dict__.keys())[:5])
print("Instance namespace:", obj.__dict__)

# Size comparison
print(f"\nClass dict size: {sys.getsizeof(Example.__dict__)} bytes")
print(f"Instance dict size: {sys.getsizeof(obj.__dict__)} bytes")

# Attribute lookup chain
print(f"\nMRO: {[c.__name__ for c in Example.__mro__]}")

Output

Click "Run" to execute your code

Understanding the internals helps with advanced debugging and framework development.

Challenge

Try modifying the code above to explore different behaviors. Can you extend the example to handle a new use case?

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__annotations__ — Expert Playground

Challenge

annotations — Expert Playground