Function format_float_scientific

numpy/_core/arrayprint.py:1140–1217

Format a floating-point scalar as a decimal string in scientific notation. Provides control over rounding, trimming and padding. Uses and assumes IEEE unbiased rounding. Uses the "Dragon4" algorithm. Parameters ---------- x : python float or numpy floating scalar V

(x, precision=None, unique=True, trim='k',
                            sign=False, pad_left=None, exp_digits=None,
                            min_digits=None)

@set_module('numpy')
def format_float_scientific(x, precision=None, unique=True, trim='k',
                            sign=False, pad_left=None, exp_digits=None,
                            min_digits=None):
    """
    Format a floating-point scalar as a decimal string in scientific notation.

    Provides control over rounding, trimming and padding. Uses and assumes
    IEEE unbiased rounding. Uses the "Dragon4" algorithm.

    Parameters
    ----------
    x : python float or numpy floating scalar
        Value to format.
    precision : non-negative integer or None, optional
        Maximum number of digits to print. May be None if `unique` is
        `True`, but must be an integer if unique is `False`.
    unique : boolean, optional
        If `True`, use a digit-generation strategy which gives the shortest
        representation which uniquely identifies the floating-point number from
        other values of the same type, by judicious rounding. If `precision`
        is given fewer digits than necessary can be printed. If `min_digits`
        is given more can be printed, in which cases the last digit is rounded
        with unbiased rounding.
        If `False`, digits are generated as if printing an infinite-precision
        value and stopping after `precision` digits, rounding the remaining
        value with unbiased rounding
    trim : one of 'k', '.', '0', '-', optional
        Controls post-processing trimming of trailing digits, as follows:

        * 'k' : keep trailing zeros, keep decimal point (no trimming)
        * '.' : trim all trailing zeros, leave decimal point
        * '0' : trim all but the zero before the decimal point. Insert the
          zero if it is missing.
        * '-' : trim trailing zeros and any trailing decimal point
    sign : boolean, optional
        Whether to show the sign for positive values.
    pad_left : non-negative integer, optional
        Pad the left side of the string with whitespace until at least that
        many characters are to the left of the decimal point.
    exp_digits : non-negative integer, optional
        Pad the 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