reverse.py

from hypothesis import given
from hypothesis.strategies import text

def reverse(string):
    return string

@given(text())
def test_reverse_reverse_is_the_original(s):
    assert s == reverse(reverse(s))

@given(text())
def test_reversed_has_same_length(s):
    assert len(s) == len(reverse(s))

@given(text())
def test_first_char_ends_up_in_last_place(s):
    if not s:
        pass
    else:
        assert s[0] == reverse(s)[-1]

stack.py

from hypothesis import given
from hypothesis.strategies import text, lists


class Stack():

    last_elem = None

    def Push(self, elem):
        self.last_elem = elem

    def Pop(self):
        return self.last_elem


@given(lists(elements=text(), min_size=1))
def test_pop_after_a_push_returns_the_pushed_value(items):
    stack = Stack()
    for elem in items:
        stack.Push(elem)
    assert stack.Pop() == items[-1]