"""
TESTS is a dict with all you tests.
Keys for this will be categories' names.
Each test is dict with
    "input" -- input data for user function
    "answer" -- your right answer
    "explanation" -- not necessary key, it's using for additional info in animation.
"""

TESTS = {
    "Basics": [
        {
            "input": "$5.34",
            "two": "$5.34"
        }          
    ]
}

"""
TESTS is a dict with all you tests.
Keys for this will be categories' names.
Each test is dict with
    "input" -- input data for user function
    "answer" -- your right answer
    "explanation" -- not necessary key, it's using for additional info in animation.
"""

TESTS = {
    "Basics": [
        {
            "input": "$5.34",
            "answer": lambda:0
        }          
    ]
}

Update tests.py