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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 _format_bf(bf, precision=3, trim='0'):
 """Format BF10 to floating point or scientific notation. """

    if bf >= 1e4 or bf <= 1e-4:
        out = np.format_float_scientific(bf, precision=precision, trim=trim)
    else:
        out = np.format_float_positional(bf, precision=precision, trim=trim)
    return out