xy_balance

Requirements:

• access a single character

• loop through a string (while)

• if, elif, else

• returning a value

We’ll say that a String is xy-balanced if for all the ‘x’ chars in the string, there exists a ‘y’ char somewhere later in the string. So “xxy” is balanced, but “xyx” is not. One ‘y’ can balance multiple ‘x’s. Return true if the given string is xy-balanced.

xy_balance("aaxbby") -> true
xy_balance("aaxbb") -> false
xy_balance("yaaxbb") -> false

This exercise was taken from codingbat.com and has been adapted for the Python language. There are many great programming exercises there, but the majority are created for Java.

Starter Code

def xy_balance(string: str) -> bool:
    pass


result = xy_balance('aaxbby')
print(result)

Tests

from main import xy_balance


def test_xy_balance_1():
    assert xy_balance('aaxbby') == True


def test_xy_balance_2():
    assert xy_balance('aaxbb') == False


def test_xy_balance_3():
    assert xy_balance('yaaxbb') == False


def test_xy_balance_4():
    assert xy_balance('yaaxbby') == True


def test_xy_balance_5():
    assert xy_balance('xaxxbby') == True


def test_xy_balance_6():
    assert xy_balance('xaxxbbyx') == False


def test_xy_balance_7():
    assert xy_balance('xxbxy') == True


def test_xy_balance_8():
    assert xy_balance('xxbx') == False


def test_xy_balance_9():
    assert xy_balance('bbb') == True


def test_xy_balance_10():
    assert xy_balance('bxbb') == False


def test_xy_balance_11():
    assert xy_balance('bxyb') == True


def test_xy_balance_12():
    assert xy_balance('xy') == True


def test_xy_balance_13():
    assert xy_balance('y') == True


def test_xy_balance_14():
    assert xy_balance('x') == False


def test_xy_balance_15():
    assert xy_balance('') == True


def test_xy_balance_16():
    assert xy_balance('yxyxyxyx') == False


def test_xy_balance_17():
    assert xy_balance('yxyxyxyxy') == True


def test_xy_balance_18():
    assert xy_balance('12xabxxydxyxyzz') == True