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.. start-badges
| |docs| |gh_actions| |codecov|
| |pypi| |supported-versions| |supported-implementations|
.. |docs| image:: https://img.shields.io/readthedocs/prefixed.svg?style=plastic&logo=read-the-docs
:target: https://prefixed.readthedocs.org
:alt: Documentation Status
.. |gh_actions| image:: https://img.shields.io/github/actions/workflow/status/Rockhopper-Technologies/prefixed/tests.yml?event=push&logo=github-actions&style=plastic
:target: https://github.com/Rockhopper-Technologies/prefixed/actions/workflows/tests.yml
:alt: GitHub Actions Status
.. |travis| image:: https://img.shields.io/travis/com/Rockhopper-Technologies/prefixed.svg?style=plastic&logo=travis
:target: https://travis-ci.com/Rockhopper-Technologies/prefixed
:alt: Travis-CI Build Status
.. |codecov| image:: https://img.shields.io/codecov/c/github/Rockhopper-Technologies/prefixed.svg?style=plastic&logo=codecov
:target: https://codecov.io/gh/Rockhopper-Technologies/prefixed
:alt: Coverage Status
.. |pypi| image:: https://img.shields.io/pypi/v/prefixed.svg?style=plastic&logo=pypi
:alt: PyPI Package latest release
:target: https://pypi.python.org/pypi/prefixed
.. |supported-versions| image:: https://img.shields.io/pypi/pyversions/prefixed.svg?style=plastic&logo=pypi
:alt: Supported versions
:target: https://pypi.python.org/pypi/prefixed
.. |supported-implementations| image:: https://img.shields.io/pypi/implementation/prefixed.svg?style=plastic&logo=pypi
:alt: Supported implementations
:target: https://pypi.python.org/pypi/prefixed
.. end-badges
Overview
========
Prefixed provides an alternative implementation of the built-in float_ which supports
formatted output with `SI (decimal)`_ and `IEC (binary)`_ prefixes.
.. code-block:: python
>>> from prefixed import Float
>>> f'{Float(3250):.2h}'
'3.25k'
>>> '{:.2h}s'.format(Float(.00001534))
'15.34μs'
>>> '{:.2k}B'.format(Float(42467328))
'40.50MiB'
>>> f'{Float(2048):.2m}B'
'2.00KB'
Because `prefixed.Float`_ inherits from the built-in float_, it behaves
exactly the same in most cases.
When a math operation is performed with another real number type
(float_, int_), the result will be a `prefixed.Float`_ instance.
Presentation Types
^^^^^^^^^^^^^^^^^^
Additional presentation types ``'h'``, ``'H'``, ``'k'``, ``'K'``,
``'m'``, and ``'M'`` are supported for f-strings and `format()`_.
+---------+-------------------------------------------------------------------+
| Type | Meaning |
+=========+===================================================================+
| ``'h'`` | SI format. Outputs the number with closest divisible SI prefix. |
| | (k, M, G, ...) |
+---------+-------------------------------------------------------------------+
| ``'H'`` | Same as ``'h'`` with precision indicating significant digits. |
+---------+-------------------------------------------------------------------+
| ``'k'`` | IEC Format. Outputs the number with closest divisible IEC prefix. |
| | (Ki, Mi, Gi, ...) |
+---------+-------------------------------------------------------------------+
| ``'K'`` | Same as ``'k'`` with precision indicating significant digits. |
+---------+-------------------------------------------------------------------+
| ``'m'`` | Short IEC Format. Same as ``'k'`` but only a single character. |
| | (K, M, G, ...) |
+---------+-------------------------------------------------------------------+
| ``'M'`` | Same as ``'m'`` with precision indicating significant digits. |
+---------+-------------------------------------------------------------------+
| | |
+---------+-------------------------------------------------------------------+
| ``'j'`` | Alias for ``'k'`` - DEPRECATED |
+---------+-------------------------------------------------------------------+
| ``'J'`` | Alias for ``'m'`` - DEPRECATED |
+---------+-------------------------------------------------------------------+
String Initialization
^^^^^^^^^^^^^^^^^^^^^
When initializing from strings, SI and IEC prefixes are honored
.. code-block:: python
>>> Float('2k')
Float(2000.0)
>>> Float('2Ki')
Float(2048.0)
Additional Flags
^^^^^^^^^^^^^^^^
An additional format flag '!' is available which adds a space before the prefix
.. code-block:: python
>>> f'{Float(3250):!.2h}'
'3.25 k'
Significant Digits
^^^^^^^^^^^^^^^^^^
When the ``'H'``, ``'K``, or ``'M'`` presentation types are used, precision is treated as
the number of `significant digits`_ to include. Standard rounding will occur for the final digit.
.. code-block:: python
>>> f'{Float(1246):.3h}'
'1.246k'
>>> f'{Float(1246):.3H}'
'1.25k'
By default, trailing zeros are removed.
.. code-block:: python
>>> f'{Float(1000):.3H}'
'1k'
To preserve trailing zeros, include the ``'#'`` flag.
.. code-block:: python
>>> f'{Float(1000):#.3H}'
'1.00k'
Adjustable Thresholds
^^^^^^^^^^^^^^^^^^^^^
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+``.
.. code-block:: python
>>> 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'
.. _SI (decimal): https://en.wikipedia.org/wiki/Metric_prefix
.. _IEC (binary): https://en.wikipedia.org/wiki/Binary_prefix
.. _signifigant digits: https://en.wikipedia.org/wiki/Significant_figures
Supported Prefixes
==================
SI (Decimal) Prefixes
^^^^^^^^^^^^^^^^^^^^^
+--------+--------+----------+
| Prefix | Name | Base |
+========+========+==========+
| Q | Quetta | |10^30| |
+--------+--------+----------+
| R | Ronna | |10^27| |
+--------+--------+----------+
| Y | Yotta | |10^24| |
+--------+--------+----------+
| Z | Zetta | |10^21| |
+--------+--------+----------+
| E | Exa | |10^18| |
+--------+--------+----------+
| P | Peta | |10^15| |
+--------+--------+----------+
| T | Tera | |10^12| |
+--------+--------+----------+
| G | Giga | |10^9| |
+--------+--------+----------+
| M | Mega | |10^6| |
+--------+--------+----------+
| k | Kilo | |10^3| |
+--------+--------+----------+
| 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| |
+--------+--------+----------+
| r | Ronto | |10^-27| |
+--------+--------+----------+
| q | Quecto | |10^-30| |
+--------+--------+----------+
IEC (Binary) Prefixes
^^^^^^^^^^^^^^^^^^^^^
+--------+------+--------+
| Prefix | Name | Base |
+========+======+========+
| Y | Yobi | |2^80| |
+--------+------+--------+
| Z | Zebi | |2^70| |
+--------+------+--------+
| E | Exbi | |2^60| |
+--------+------+--------+
| P | Pedi | |2^50| |
+--------+------+--------+
| T | Tebi | |2^40| |
+--------+------+--------+
| G | Gibi | |2^30| |
+--------+------+--------+
| M | Mebi | |2^20| |
+--------+------+--------+
| K | Kibi | |2^10| |
+--------+------+--------+
.. _SI (decimal): https://en.wikipedia.org/wiki/Metric_prefix
.. _IEC (binary): https://en.wikipedia.org/wiki/Binary_prefix
.. _float: https://docs.python.org/3/library/functions.html#float
.. _int: https://docs.python.org/3/library/functions.html#int
.. _prefixed.Float: https://prefixed.readthedocs.io/en/stable/api.html#prefixed.Float
.. _format(): https://docs.python.org/3/library/functions.html#format
.. |10^30| replace:: 10\ :sup:`30`\
.. |10^27| replace:: 10\ :sup:`27`\
.. |10^24| replace:: 10\ :sup:`24`\
.. |10^21| replace:: 10\ :sup:`21`\
.. |10^18| replace:: 10\ :sup:`18`\
.. |10^15| replace:: 10\ :sup:`15`\
.. |10^12| replace:: 10\ :sup:`12`\
.. |10^9| replace:: 10\ :sup:`9`\
.. |10^6| replace:: 10\ :sup:`6`\
.. |10^3| replace:: 10\ :sup:`3`\
.. |10^-3| replace:: 10\ :sup:`-3`\
.. |10^-6| replace:: 10\ :sup:`-6`\
.. |10^-9| replace:: 10\ :sup:`-9`\
.. |10^-12| replace:: 10\ :sup:`-12`\
.. |10^-15| replace:: 10\ :sup:`-15`\
.. |10^-18| replace:: 10\ :sup:`-18`\
.. |10^-21| replace:: 10\ :sup:`-21`\
.. |10^-24| replace:: 10\ :sup:`-24`\
.. |10^-27| replace:: 10\ :sup:`-27`\
.. |10^-30| replace:: 10\ :sup:`-30`\
.. |2^80| replace:: 2\ :sup:`80`\
.. |2^70| replace:: 2\ :sup:`70`\
.. |2^60| replace:: 2\ :sup:`60`\
.. |2^50| replace:: 2\ :sup:`50`\
.. |2^40| replace:: 2\ :sup:`40`\
.. |2^30| replace:: 2\ :sup:`30`\
.. |2^20| replace:: 2\ :sup:`20`\
.. |2^10| replace:: 2\ :sup:`10`\
|
