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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 _val(var, is_percent=False):
 """ Tries to determine the appropriate value of a particular variable that is passed in. If the value is supposed to be a percentage, a whole integer will be sought after and then turned into a floating point number between 0 and 1. If the value is supposed to be an integer, the variable is cast into an integer. """

    try:
        if is_percent:
            var = float(int(var.strip('%')) / 100.0)
        else:
            var = int(var)
    except ValueError:
        raise ValueError('invalid watermark parameter: ' + var)
    return var