Modifies a number pattern by specified keyword arguments.

def modify_number_pattern(number_pattern, **kwargs):
    """Modifies a number pattern by specified keyword arguments."""
    params = ['pattern', 'prefix', 'suffix', 'grouping',
              'int_prec', 'frac_prec', 'exp_prec', 'exp_plus']
    for param in params:
        if param in kwargs:
            continue
        kwargs[param] = getattr(number_pattern, param)
    return NumberPattern(**kwargs)