Solution: Disarium Number

Write a function that determines whether a number is a Disarium (True) or not (False).

Function definition

def is_disarium(n):
    total = 0
    position = 1
    for digit in str(n):
        total = total + (int(digit)**position)
        position = position + 1
    
    # return True or False
    return total == n

Using enumerate():

def is_disarium(n):
    total = 0
    for position, digit in enumerate(str(n), start=1):
        total = total + (int(digit)**position)
    
    # return True or False
    return total == n

Using enumerate() and list comprehension:

def is_disarium(n):
    return sum([int(digit)**position for position, digit in enumerate(str(n), start=1)]) == n

Testing

Check if your function returns the expected value using the cell below.

import unittest

class UnitTests(unittest.TestCase):
    def test_type(self):
        self.assertEqual(type(is_disarium(10)), type(False), 'The function should return a boolean operator')
    def test_true(self):
        self.assertEqual(is_disarium(89), True, 'The function should return True for the value 89')
    def test_false(self):
        self.assertEqual(is_disarium(100), False, 'The function should return False for the value 100')

unittest.main(argv=[''], verbosity=2,exit=False)

test_false (__main__.UnitTests) ... 

ok
test_true (__main__.UnitTests) ... 

ok
test_type (__main__.UnitTests) ... 

ok

----------------------------------------------------------------------
Ran 3 tests in 0.004s

OK

<unittest.main.TestProgram at 0x7f90700c0810>