numpy.format_float_scientific#
- numpy.format_float_scientific(x, precision=None, unique=True, trim='k', sign=False, pad_left=None, exp_digits=None, min_digits=None)[source]#
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:
- 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. 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
- 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.
- exp_digitsnon-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_digitsnon-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.
New in version 1.21.0.
- Returns:
- repstring
The string representation of the floating point value
See also
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'