def use_calculator()

in grade_school_math/calculator.py [0:0]


def use_calculator(sample):
    if "<<" not in sample:
        return None

    parts = sample.split("<<")
    remaining = parts[-1]
    if ">>" in remaining:
        return None
    if "=" not in remaining:
        return None
    lhs = remaining.split("=")[0]
    lhs = lhs.replace(",", "")
    if any([x not in "0123456789*+-/.()" for x in lhs]):
        return None
    return eval_with_timeout(lhs)