prefixed 0.3.1

Prefixed alternative numeric library

Overview

Prefixed provides an alternative implementation of the built-in float which supports formatted output with SI (decimal) and IEC (binary) prefixes.

>>> from prefixed import Float

>>> f'{Float(3250):.2h}'
'3.25k'

>>> '{:.2h}s'.format(Float(.00001534))
'15.34μs'

>>> '{:.2j}B'.format(Float(42467328))
'40.50MiB'

>>> f'{Float(2048):.2J}B'
'2.00KB'

Because prefixed.Float inherits from the built-in float, it behaves exactly the same in most cases.

Key differences:

• When a math operation is performed with another real number type (float, int), the result will be a prefixed.Float instance.

• Additional presentation types 'h', 'j', and 'J' are supported for f-strings and format().

  Type	Meaning
  'h'	SI format. Outputs the number with closest divisible SI prefix. (k, M, G, …)
  'j'	IEC Format. Outputs the number with closest divisible IEC prefix. (Ki, Mi, Gi, …)
  'J'	Short IEC Format. Same as 'j' but only a single character. (K, M, G, …)

• When initializing from strings, SI and IEC prefixes are honored

>>> Float('2k')
Float(2000.0)

>>> Float('2Ki')
Float(2048.0)

• An additional format flag ‘!’ is available which adds a space before the prefix

>>> f'{Float(3250):!.2h}'
'3.25 k'

• An additional field, margin, can be specified which lowers or raises the threshold for for each prefix by the given percentage. Margin is specified before precision with the syntax %[-]digit+.

>>> f'{Float(950):.2h}'
'950.00'

>>> f'{Float(950):%-5.2h}'
'0.95k'

>>> f'{Float(1000):%5.2h}'
'1000.00'

>>> f'{Float(1050):%5.2h}'
1.05k'

Supported Prefixes

SI (Decimal) Prefixes

Prefix	Name	Base
Y	Yotta	1024
Z	Zetta	1021
E	Exa	1018
P	Peta	1015
T	Tera	1012
G	Giga	109
M	Mega	106
k	Kilo	103
m	Milli	10-3
μ	Micro	10-6
n	Nano	10-9
p	Pico	10-12
f	Femto	10-15
a	Atto	10-18
z	Zepto	10-21
y	Yocto	10-24

IEC (Binary) Prefixes

Prefix	Name	Base
Y	Yobi	1080
Z	Zebi	1070
E	Exbi	1060
P	Pedi	1050
T	Tebi	1040
G	Gibi	1030
M	Mebi	1020
K	Kibi	1010