test.py

import io, sys, os, re, pytest
sys.stdout = buffer = io.StringIO()

import app

@pytest.mark.it("Create a variable named my_var1")
def test_my_var1_exists():
    try:
        from app import my_var1
    except ImportError:
        raise ImportError("The variable 'my_var1' should exist on app.py")

@pytest.mark.it("Create a variable named my_var2")
def test_my_var2_exists():
    try:
        from app import my_var2
    except ImportError:
        raise ImportError("The variable 'my_var2' should exist on app.py")

@pytest.mark.it("Variable my_var1 value should be 'Hello'")
def test_my_var1_value():
    from app import my_var1
    assert  my_var1.lower() == "hello"

@pytest.mark.it("Variable my_var2 value should be 'World'")
def test_my_var2_value():
    from app import my_var2
    assert   my_var2.lower() == "world"

@pytest.mark.it("Don't remove the_new_string variable")
def test_the_new_string_exists():
    import app
    try:
        app.the_new_string
    except AttributeError:
        raise AttributeError('The variable "the_new_string" should exist on app.py')

@pytest.mark.it('Print "Hello World" on the console')
def test_for_file_output():
    captured = buffer.getvalue()
    assert "hello world\n" in captured.lower() #add \n because the console jumps the line on every print