Source: 📖 Python Cookbook ch8.20 p305

Calling methods with string names

If you have the name of a method stored as a string, this can be used to call the method itself with getattr(). First you lookup the method, then you pass arguments to it.

class Nums:
	def __init__(self, x, y):
		self.x = x
		self.y = y
		
	def add(self, extra_num=0):
		return self.x + self.y + extra_num


a = Nums(2, 3)

result = getattr(a, 'add')(4)	# Calls `add` on `a`, with the argument `4` = 9

The getattr() function takes an object (a), an attribute to look for as a string ('add') and returns the attribute found. Since the attribute found is a callable method, we can supply it with an argument inside brackets straight after ((4)).