def test_no_sub_is_different():
source = "aabbc"
target = "aabbz"
assert levenshtein(source, target) != levenshtein_no_sub(source, target)
def test_levenshtein_no_subboth_empty():
source = ""
target = ""
gold = 0
assert levenshtein_no_sub(source, target) == gold
def test_levenshtein_no_sub_empty_target():
source = "aaaaa"
target = ""
gold = len(source) * 1
assert levenshtein_no_sub(source, target) == gold
def test_levenshtein_no_sub_longer_target():
source = "aaaaa"
target = "aaaaaaaa"
gold = abs(len(source) - len(target)) * 1
assert levenshtein_no_sub(source, target) == gold
def test_levenshtein_no_sub():
source = "intention"
target = "execution"
gold = 8
assert levenshtein_no_sub(source, target) == gold
def real_test(source, target):
lcs = longest_common_subsequence(source, target)
gold = levenshtein_no_sub(source, target)
assert (len(source) + len(target) - (2 * lcs)) == gold