Understanding Reflection in Python

Reflection in Python is a powerful feature that allows you to inspect and modify the structure of objects at runtime. This means you can dynamically examine the properties and methods of objects, enhancing flexibility in your coding practices.

Key Concepts

• Reflection: The ability of a program to examine and modify its own structure and behavior.
• Introspection: A subset of reflection that allows you to examine the type or properties of an object (e.g., its attributes and methods).

Main Features of Reflection in Python

1. Getting Object Details:
   • You can retrieve details about an object using the built-in dir() function.
   • Example:
2. Checking Object Type:
   • Use the type() function to determine the type of an object.
   • Example:
3. Inspecting Attributes and Methods:
   • Use getattr() to access an attribute or method dynamically.
   • Example:
4. Modifying Attributes:
   • You can also set attributes dynamically using setattr().
   • Example:
5. Deleting Attributes:
   • Use delattr() to delete an attribute from an object.
   • Example:

delattr(obj, 'new_attribute')
print(hasattr(obj, 'new_attribute'))  # Outputs: False

setattr(obj, 'new_attribute', 42)
print(obj.new_attribute)  # Outputs: 42

method_name = 'my_method'
method = getattr(obj, method_name)
print(method)  # Outputs: <bound method MyClass.my_method of <__main__.MyClass object at 0x...>>

print(type(obj))  # Outputs: <class '__main__.MyClass'>

class MyClass:
    def my_method(self):
        pass

obj = MyClass()
print(dir(obj))  # Lists all attributes and methods of obj

Conclusion

Reflection is a useful feature in Python that enhances flexibility and allows for dynamic programming. By understanding and utilizing reflection, you can create more adaptable and reusable code.

Summary of Functions

• dir(object): Lists all attributes and methods of the object.
• type(object): Returns the type of the object.
• getattr(object, name): Retrieves an attribute or method by name.
• setattr(object, name, value): Sets an attribute or method dynamically.
• delattr(object, name): Deletes an attribute from an object.

This summary provides a foundational understanding of reflection in Python, making it easier for beginners to explore and utilize this feature in their programming endeavors.