last_chars

Given 2 strings, a and b, return a new string made of the first char of a and the last char of b, so “yo” and “java” yields “ya”. If either string is length 0, use ‘@’ for its missing char.

last_chars("last", "chars") -> "ls"
last_chars("yo", "java") -> "ya"
last_chars("hi", "") -> "h@"

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 last_chars(a: str, b: str) -> str:
    pass


result = last_chars('last', 'chars')
print(result)

Tests

from main import last_chars


def test_last_chars_1():
    assert last_chars('last', 'chars') == 'ls'


def test_last_chars_2():
    assert last_chars('yo', 'java') == 'ya'


def test_last_chars_3():
    assert last_chars('hi', '') == 'h@'


def test_last_chars_4():
    assert last_chars('', 'hello') == '@o'


def test_last_chars_5():
    assert last_chars('', '') == '@@'


def test_last_chars_6():
    assert last_chars('kitten', 'hi') == 'ki'


def test_last_chars_7():
    assert last_chars('k', 'zip') == 'kp'


def test_last_chars_8():
    assert last_chars('kitten', '') == 'k@'


def test_last_chars_9():
    assert last_chars('kitten', 'zip') == 'kp'