he exponent with zeros until it contains at least this many digits.
        If omitted, the exponent will be at least 2 digits.
    min_digits : non-negative integer or None, optional
        Minimum number of digits to print. This only has an effect for
        `unique=True`. In that case more digits than necessary to uniquely
        identify the value may be printed and rounded unbiased.

        -- versionadded:: 1.21.0

    Returns
    -------
    rep : string
        The string representation of the floating point value

    See Also
    --------
    format_float_positional

    Examples
    --------
    >>> np.format_float_scientific(np.float32(np.pi))
    '3.1415927e+00'
    >>> s = np.float32(1.23e24)
    >>> np.format_float_scientific(s, unique=False, precision=15)
    '1.230000071797338e+24'
    >>> np.format_float_scientific(s, exp_digits=4)
    '1.23e+0024'
    r1