I've been fiddling around with some easy code challenges and there's one about determining if a triangle is equilateral, isosceles, or scalene.
I've come up with a working solution, but I feel this could be greatly improved and/or simplified.
The sides of a triangle come in a list e.g. [2, 2, 2] or [0, 0, 0].
Here's what I've got.
def is_triangle(sides):
if min(sides) <= 0:
return False
if sum(sorted(sides)[:-1]) < sorted(sides)[-1]:
return False
return True
def equilateral(sides):
triangle = is_triangle(sides)
if triangle:
x, y, z = sides
return x == y == z
else:
return False
def isosceles(sides):
triangle = is_triangle(sides)
if triangle:
x, y, z = sides
return x == y or y == z or z == x
else:
return False
def scalene(sides):
if equilateral(sides) or isosceles(sides):
return False
return is_triangle(sides)
Also, I'm adding a simple unit test module.
import unittest
from triangle import equilateral, isosceles, scalene
class TestEquilateralTriangle(unittest.TestCase):
def test_all_sides_are_equal(self):
self.assertIs(equilateral([2, 2, 2]), True)
def test_all_zero_sides_is_not_a_triangle(self):
self.assertIs(equilateral([0, 0, 0]), False)
def test_third_triangle_inequality_violation(self):
self.assertIs(isosceles([3, 1, 1]), False)
def test_sides_may_be_floats(self):
self.assertIs(equilateral([0.5, 0.5, 0.5]), True)
class TestIsoscelesTriangle(unittest.TestCase):
def test_last_two_sides_are_equal(self):
self.assertIs(isosceles([3, 4, 4]), True)
def test_equilateral_triangles_are_also_isosceles(self):
self.assertIs(isosceles([4, 4, 4]), True)
def test_third_triangle_inequality_violation(self):
self.assertIs(isosceles([3, 1, 1]), False)
def test_sides_may_be_floats(self):
self.assertIs(isosceles([0.5, 0.4, 0.5]), True)
class TestScaleneTriangle(unittest.TestCase):
def test_no_sides_are_equal(self):
self.assertIs(scalene([5, 4, 6]), True)
def test_all_sides_are_equal(self):
self.assertIs(scalene([4, 4, 4]), False)
def test_third_triangle_inequality_violation(self):
self.assertIs(isosceles([3, 1, 1]), False)
if __name__ == "__main__":
unittest.main()
I'd appreciate some feedback on my code.