def test_validates_nucleotides(self): with self.assertRaises(ValueError): count("GACT", 'X')
def test_counts_only_thymidine(self): self.assertEqual(1, count('GGGGGTAACCCGG', 'T'))
def test_dna_has_no_uracil(self): self.assertEqual(0, count('GATTACA', 'U'))
def test_empty_dna_string_has_no_adenosine(self): self.assertEqual(0, count('', 'A'))
def test_repetitive_cytidine_gets_counted(self): self.assertEqual(5, count('CCCCC', 'C'))
def test_counting_nucs(self): self.assertEqual((20, 12, 17, 21), dna.count('AGCTTTTCATTCTGACTGCAACGGGCAATATGTCTCTGTGTGGATTAAAAAAAGAGTGTCTGATAGCAGC'))