numpy.format_float_positional — NumPy v2.2 Manual (original) (raw)

numpy.format_float_positional(x, precision=None, unique=True, fractional=True, trim='k', sign=False, pad_left=None, pad_right=None, min_digits=None)[source]#

Format a floating-point scalar as a decimal string in positional notation.

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

Parameters:

xpython float or numpy floating scalar

Value to format.

precisionnon-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.

uniqueboolean, 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, or 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

fractionalboolean, optional

If True, the cutoffs of precision and min_digits refer to the total number of digits after the decimal point, including leading zeros. If False, precision and min_digits refer to the total number of significant digits, before or after the decimal point, ignoring leading zeros.

trimone 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

signboolean, optional

Whether to show the sign for positive values.

pad_leftnon-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.

pad_rightnon-negative integer, optional

Pad the right side of the string with whitespace until at least that many characters are to the right of the decimal point.

min_digitsnon-negative integer or None, optional

Minimum number of digits to print. Only has an effect if _unique=True_in which case additional digits past those necessary to uniquely identify the value may be printed, rounding the last additional digit.

New in version 1.21.0.

Returns:

repstring

The string representation of the floating point value

Examples

import numpy as np np.format_float_positional(np.float32(np.pi)) '3.1415927' np.format_float_positional(np.float16(np.pi)) '3.14' np.format_float_positional(np.float16(0.3)) '0.3' np.format_float_positional(np.float16(0.3), unique=False, precision=10) '0.3000488281'