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@scogle
Created Feb 12, 2018
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import unittest
def flatten(arr):
""" Write some code, that will flatten an array of arbitrarily nested arrays
of integers into a flat array of integers. e.g. [[1,2,[3]],4] -> [1,2,3,4].
"""
flattened_arr = []
def recur(el):
if type(el) == list:
for e in el:
recur(e)
elif type(el) == int:
flattened_arr.append(el)
else:
raise TypeError('List elements must be integers or lists')
recur(arr)
return flattened_arr
class TestFlattener(unittest.TestCase):
print(flatten([[1,2,[3]],4]))
def test_flatten(self):
""" Test that the flattener works correctly
"""
test_arr = [[1,2,[3]],4]
res = flatten(test_arr)
self.assertEqual(res, [1,2,3,4])
def test_error(self):
""" Test that the appropriate exception gets raised on bad input
"""
with self.assertRaises(TypeError) as te:
flatten([[1,{'hello': 'world'},['a']],4])
self.assertEqual(type(te.exception), TypeError)
if __name__ == '__main__':
unittest.main()
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