change_xy

Given a string, compute recursively (no loops) a new string where all the lowercase 'x' chars have been changed to 'y' chars.

change_xy("codex") -> "codey"
change_xy("xxhixx") -> "yyhiyy"
change_xy("xhixhix") -> "yhiyhiy"

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 change_xy(string: str) -> str:
    pass


result = change_xy('codex')
print(result)

Tests

from main import change_xy


def test_change_xy_1():
    assert change_xy('codex') == 'codey'


def test_change_xy_2():
    assert change_xy('xxhixx') == 'yyhiyy'


def test_change_xy_3():
    assert change_xy('xhixhix') == 'yhiyhiy'


def test_change_xy_4():
    assert change_xy('hiy') == 'hiy'


def test_change_xy_5():
    assert change_xy('h') == 'h'


def test_change_xy_6():
    assert change_xy('x') == 'y'


def test_change_xy_7():
    assert change_xy('') == ''


def test_change_xy_8():
    assert change_xy('xxx') == 'yyy'


def test_change_xy_9():
    assert change_xy('yyhxyi') == 'yyhyyi'


def test_change_xy_10():
    assert change_xy('hihi') == 'hihi'


def test_change_xy_11():
    assert change_xy('XxXx') == 'XyXy'