#!/usr/bin/env python

# -*- coding: utf-8 -*-

# Triangle Project Code.

# triangle(a, b, c) analyzes the lengths of the sides of a triangle

# (represented by a, b and c) and returns the type of triangle.

#

# It returns:

# 'equilateral' if all sides are equal

# 'isosceles' if exactly 2 sides are equal

# 'scalene' if no sides are equal

#

# The tests for this method can be found in

# about_triangle_project.py

# and

# about_triangle_project_2.py

#

def triangle(a, b, c):

sides = sorted([a,b,c])

for side in sides:

if side < 1: raise TriangleError

if sides[0] + sides[1] < sides[2]: raise TriangleError

set_of_sides = set(sides)

if len(set_of_sides) == 1:

return 'equilateral'

elif len(set_of_sides) == 2:

return 'isosceles'

return 'scalene'

# Error class used in part 2. No need to change this code.

class TriangleError(StandardError):

pass