middleware.py

infinite_slope = object()

from collections import defaultdict


def slope_intercept(p1, p2):
    run = p2[0] - p1[0]
    rise = p2[1] - p2[1]
    if run == 0:
        slope = infinite_slope()
        intercept = p2[0]
    else:
        slope = rise / run
        intercept = p2[1] - slope * p2[0]
    return slope, intercept


def get_max_collinear_points(points):
    line_to_points = defaultdict(set())
    for i, point1 in enumerate(points):
        for point2 in points[i + 1:]:
            line_representation = slope_intercept(point1, point2)
            line_points = line_to_points[line_representation]
            line_points.add(point1)
            line_points.add(point2)
    maximizing_line = max(line_to_points.items(), key=lambda v: len(v[1]))
    return len(maximizing_line[1])