humanfriendly: Human friendly input/output in Python
====================================================

.. image:: https://github.com/xolox/python-humanfriendly/actions/workflows/test.yml/badge.svg?branch=master
   :target: https://github.com/xolox/python-humanfriendly/actions

.. image:: https://codecov.io/gh/xolox/python-humanfriendly/branch/master/graph/badge.svg?token=jYaj4T74TU
   :target: https://codecov.io/gh/xolox/python-humanfriendly

The functions and classes in the `humanfriendly` package can be used to make
text interfaces more user friendly. Some example features:

- Parsing and formatting numbers, file sizes, pathnames and timespans in
  simple, human friendly formats.

- Easy to use timers for long running operations, with human friendly
  formatting of the resulting timespans.

- Prompting the user to select a choice from a list of options by typing the
  option's number or a unique substring of the option.

- Terminal interaction including text styling (`ANSI escape sequences`_), user
  friendly rendering of usage messages and querying the terminal for its
  size.

The `humanfriendly` package is currently tested on Python 2.7, 3.5+ and PyPy
(2.7) on Linux and macOS. While the intention is to support Windows as well,
you may encounter some rough edges.

.. contents::
   :local:

Getting started
---------------

It's very simple to start using the `humanfriendly` package::

   >>> from humanfriendly import format_size, parse_size
   >>> from humanfriendly.prompts import prompt_for_input
   >>> user_input = prompt_for_input("Enter a readable file size: ")

     Enter a readable file size: 16G

   >>> num_bytes = parse_size(user_input)
   >>> print(num_bytes)
   16000000000
   >>> print("You entered:", format_size(num_bytes))
   You entered: 16 GB
   >>> print("You entered:", format_size(num_bytes, binary=True))
   You entered: 14.9 GiB

To get a demonstration of supported terminal text styles (based on
`ANSI escape sequences`_) you can run the following command::

   $ humanfriendly --demo

Command line
------------

.. A DRY solution to avoid duplication of the `humanfriendly --help' text:
..
.. [[[cog
.. from humanfriendly.usage import inject_usage
.. inject_usage('humanfriendly.cli')
.. ]]]

**Usage:** `humanfriendly [OPTIONS]`

Human friendly input/output (text formatting) on the command
line based on the Python package with the same name.

**Supported options:**

.. csv-table::
   :header: Option, Description
   :widths: 30, 70


   "``-c``, ``--run-command``","Execute an external command (given as the positional arguments) and render
   a spinner and timer while the command is running. The exit status of the
   command is propagated."
   ``--format-table``,"Read tabular data from standard input (each line is a row and each
   whitespace separated field is a column), format the data as a table and
   print the resulting table to standard output. See also the ``--delimiter``
   option."
   "``-d``, ``--delimiter=VALUE``","Change the delimiter used by ``--format-table`` to ``VALUE`` (a string). By default
   all whitespace is treated as a delimiter."
   "``-l``, ``--format-length=LENGTH``","Convert a length count (given as the integer or float ``LENGTH``) into a human
   readable string and print that string to standard output."
   "``-n``, ``--format-number=VALUE``","Format a number (given as the integer or floating point number ``VALUE``) with
   thousands separators and two decimal places (if needed) and print the
   formatted number to standard output."
   "``-s``, ``--format-size=BYTES``","Convert a byte count (given as the integer ``BYTES``) into a human readable
   string and print that string to standard output."
   "``-b``, ``--binary``","Change the output of ``-s``, ``--format-size`` to use binary multiples of bytes
   (base-2) instead of the default decimal multiples of bytes (base-10)."
   "``-t``, ``--format-timespan=SECONDS``","Convert a number of seconds (given as the floating point number ``SECONDS``)
   into a human readable timespan and print that string to standard output."
   ``--parse-length=VALUE``,"Parse a human readable length (given as the string ``VALUE``) and print the
   number of metres to standard output."
   ``--parse-size=VALUE``,"Parse a human readable data size (given as the string ``VALUE``) and print the
   number of bytes to standard output."
   ``--demo``,"Demonstrate changing the style and color of the terminal font using ANSI
   escape sequences."
   "``-h``, ``--help``",Show this message and exit.

.. [[[end]]]

A note about size units
-----------------------

When I originally published the `humanfriendly` package I went with binary
multiples of bytes (powers of two). It was pointed out several times that this
was a poor choice (see issue `#4`_ and pull requests `#8`_ and `#9`_) and thus
the new default became decimal multiples of bytes (powers of ten):

+------+---------------+---------------+
| Unit | Binary value  | Decimal value |
+------+---------------+---------------+
| KB   |          1024 |          1000 +
+------+---------------+---------------+
| MB   |       1048576 |       1000000 |
+------+---------------+---------------+
| GB   |    1073741824 |    1000000000 |
+------+---------------+---------------+
| TB   | 1099511627776 | 1000000000000 |
+------+---------------+---------------+
| etc  |               |               |
+------+---------------+---------------+

The option to use binary multiples of bytes remains by passing the keyword
argument `binary=True` to the `format_size()`_ and `parse_size()`_ functions.

Windows support
---------------

Windows 10 gained native support for ANSI escape sequences which means commands
like ``humanfriendly --demo`` should work out of the box (if your system is
up-to-date enough). If this doesn't work then you can install the colorama_
package, it will be used automatically once installed.

Contact
-------

The latest version of `humanfriendly` is available on PyPI_ and GitHub_. The
documentation is hosted on `Read the Docs`_ and includes a changelog_. For bug
reports please create an issue on GitHub_. If you have questions, suggestions,
etc. feel free to send me an e-mail at `peter@peterodding.com`_.

License
-------

This software is licensed under the `MIT license`_.

© 2021 Peter Odding.

.. External references:
.. _#4: https://github.com/xolox/python-humanfriendly/issues/4
.. _#8: https://github.com/xolox/python-humanfriendly/pull/8
.. _#9: https://github.com/xolox/python-humanfriendly/pull/9
.. _ANSI escape sequences: https://en.wikipedia.org/wiki/ANSI_escape_code
.. _changelog: https://humanfriendly.readthedocs.io/en/latest/changelog.html
.. _colorama: https://pypi.org/project/colorama
.. _format_size(): https://humanfriendly.readthedocs.io/en/latest/#humanfriendly.format_size
.. _GitHub: https://github.com/xolox/python-humanfriendly
.. _MIT license: https://en.wikipedia.org/wiki/MIT_License
.. _parse_size(): https://humanfriendly.readthedocs.io/en/latest/#humanfriendly.parse_size
.. _peter@peterodding.com: peter@peterodding.com
.. _PyPI: https://pypi.org/project/humanfriendly
.. _Read the Docs: https://humanfriendly.readthedocs.io
