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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def evaluate(op, op_str, a, b, use_numexpr=True, **eval_kwargs):
 """ evaluate and return the expression of the op on a and b Parameters op : the actual operand op_str: the string version of the op a : left operand b : right operand use_numexpr : whether to try to use numexpr (default True) """


    use_numexpr = use_numexpr and _bool_arith_check(op_str, a, b)
    if use_numexpr:
        return _evaluate(op, op_str, a, b, **eval_kwargs)
    return _evaluate_standard(op, op_str, a, b)