Using Python vars() to Generate a Dictionary from Object Fields

vars() function

Let’s consider the following example:

class Foo:
	def __init__(self):
		self.a = 1
		self.b = 2

The vars() function in Python returns the __dict__ attribute of an object, which is a dictionary containing the object’s attributes and their values. In the example code provided, vars(foo) returns {'a': 1, 'b': 2} because foo is an instance of the Foo class, which has attributes a and b.

foo = Foo()
print(vars(foo))  # Output: {'a': 1, 'b': 2}

This demonstrates how you can use the vars() function to inspect the attributes of an object dynamically. It’s particularly useful when you need to introspect objects or manipulate their attributes programmatically.

Modifying Object Attributes

You can also use the vars() function to modify object attributes dynamically. Let’s say we want to update the value of attribute b in the foo object:

vars(foo)['b'] = 42
print(vars(foo))  # Output: {'a': 1, 'b': 42}

Adding New Attributes

Additionally, you can add new attributes to an object using the vars() function. Let’s add a new attribute c to the foo object:

vars(foo)['c'] = 3.14
print(vars(foo))  # Output: {'a': 1, 'b': 42, 'c': 3.14}