str_count

Given a string and a non-empty substring sub, compute recursively the number of times that sub appears in the string, without the sub strings overlapping.

str_count("catcowcat", "cat") -> 2
str_count("catcowcat", "cow") -> 1
str_count("catcowcat", "dog") -> 0

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 str_count(string: str, sub: str) -> int:
    pass


result = str_count('catcowcat', 'cat')
print(result)

Tests

from main import str_count


def test_str_count_1():
    assert str_count('catcowcat', 'cat') == 2


def test_str_count_2():
    assert str_count('catcowcat', 'cow') == 1


def test_str_count_3():
    assert str_count('catcowcat', 'dog') == 0


def test_str_count_4():
    assert str_count('cacatcowcat', 'cat') == 2


def test_str_count_5():
    assert str_count('xyx', 'x') == 2


def test_str_count_6():
    assert str_count('iiiijj', 'i') == 4


def test_str_count_7():
    assert str_count('iiiijj', 'ii') == 2


def test_str_count_8():
    assert str_count('iiiijj', 'iii') == 1


def test_str_count_9():
    assert str_count('iiiijj', 'j') == 2


def test_str_count_10():
    assert str_count('iiiijj', 'jj') == 1


def test_str_count_11():
    assert str_count('aaabababab', 'ab') == 4


def test_str_count_12():
    assert str_count('aaabababab', 'aa') == 1


def test_str_count_13():
    assert str_count('aaabababab', 'a') == 6


def test_str_count_14():
    assert str_count('aaabababab', 'b') == 4