A Python loop on a list of Python objects

slow_loop.py

from random import random

class Rectangle:
    def __init__(self, w, h):
        self.w = w
        self.h = h
    def area(self):
        return self.w * self.h

def check_rectangles(rectangles, threshold):
    n_out = 0
    for rectangle in rectangles:
        if rectangle.area() > threshold:
            n_out += 1
    return n_out

def main():
    n_rectangles = 10000000
    rectangles = list(Rectangle(random(), random()) for i in range(n_rectangles))
    n_out = check_rectangles(rectangles, threshold=0.25)
    print(n_out)