pyqtgraph/pyqtgraph/util/colorama

Download and docs:
    http://pypi.python.org/pypi/colorama
Development:
    http://code.google.com/p/colorama
Discussion group:
     https://groups.google.com/forum/#!forum/python-colorama

Description
===========

Makes ANSI escape character sequences for producing colored terminal text and
cursor positioning work under MS Windows.

ANSI escape character sequences have long been used to produce colored terminal
text and cursor positioning on Unix and Macs. Colorama makes this work on
Windows, too, by wrapping stdout, stripping ANSI sequences it finds (which
otherwise show up as gobbledygook in your output), and converting them into the
appropriate win32 calls to modify the state of the terminal. On other platforms,
Colorama does nothing.

Colorama also provides some shortcuts to help generate ANSI sequences
but works fine in conjunction with any other ANSI sequence generation library,
such as Termcolor (http://pypi.python.org/pypi/termcolor.)

This has the upshot of providing a simple cross-platform API for printing
colored terminal text from Python, and has the happy side-effect that existing
applications or libraries which use ANSI sequences to produce colored output on
Linux or Macs can now also work on Windows, simply by calling
``colorama.init()``.

An alternative approach is to install 'ansi.sys' on Windows machines, which
provides the same behaviour for all applications running in terminals. Colorama
is intended for situations where that isn't easy (e.g. maybe your app doesn't
have an installer.)

Demo scripts in the source code repository prints some colored text using
ANSI sequences. Compare their output under Gnome-terminal's built in ANSI
handling, versus on Windows Command-Prompt using Colorama:

.. image:: http://colorama.googlecode.com/hg/screenshots/ubuntu-demo.png
    :width: 661
    :height: 357
    :alt: ANSI sequences on Ubuntu under gnome-terminal.

.. image:: http://colorama.googlecode.com/hg/screenshots/windows-demo.png
    :width: 668
    :height: 325
    :alt: Same ANSI sequences on Windows, using Colorama.

These screengrabs show that Colorama on Windows does not support ANSI 'dim
text': it looks the same as 'normal text'.


License
=======

Copyright Jonathan Hartley 2013. BSD 3-Clause license, see LICENSE file.


Dependencies
============

None, other than Python. Tested on Python 2.5.5, 2.6.5, 2.7, 3.1.2, and 3.2

Usage
=====

Initialisation
--------------

Applications should initialise Colorama using::

    from colorama import init
    init()

If you are on Windows, the call to ``init()`` will start filtering ANSI escape
sequences out of any text sent to stdout or stderr, and will replace them with
equivalent Win32 calls.

Calling ``init()`` has no effect on other platforms (unless you request other
optional functionality, see keyword args below.) The intention is that
applications can call ``init()`` unconditionally on all platforms, after which
ANSI output should just work.

To stop using colorama before your program exits, simply call ``deinit()``.
This will restore stdout and stderr to their original values, so that Colorama
is disabled. To start using Colorama again, call ``reinit()``, which wraps
stdout and stderr again, but is cheaper to call than doing ``init()`` all over
again.


Colored Output
--------------

Cross-platform printing of colored text can then be done using Colorama's
constant shorthand for ANSI escape sequences::

    from colorama import Fore, Back, Style
    print(Fore.RED + 'some red text')
    print(Back.GREEN + 'and with a green background')
    print(Style.DIM + 'and in dim text')
    print(Fore.RESET + Back.RESET + Style.RESET_ALL)
    print('back to normal now')

or simply by manually printing ANSI sequences from your own code::

    print('/033[31m' + 'some red text')
    print('/033[30m' # and reset to default color)

or Colorama can be used happily in conjunction with existing ANSI libraries
such as Termcolor::

    from colorama import init
    from termcolor import colored

    # use Colorama to make Termcolor work on Windows too
    init()

    # then use Termcolor for all colored text output
    print(colored('Hello, World!', 'green', 'on_red'))

Available formatting constants are::

    Fore: BLACK, RED, GREEN, YELLOW, BLUE, MAGENTA, CYAN, WHITE, RESET.
    Back: BLACK, RED, GREEN, YELLOW, BLUE, MAGENTA, CYAN, WHITE, RESET.
    Style: DIM, NORMAL, BRIGHT, RESET_ALL

Style.RESET_ALL resets foreground, background and brightness. Colorama will
perform this reset automatically on program exit.


Cursor Positioning
------------------

ANSI codes to reposition the cursor are supported. See demos/demo06.py for
an example of how to generate them.


Init Keyword Args
-----------------

``init()`` accepts some kwargs to override default behaviour.

init(autoreset=False):
    If you find yourself repeatedly sending reset sequences to turn off color
    changes at the end of every print, then ``init(autoreset=True)`` will
    automate that::

        from colorama import init
        init(autoreset=True)
        print(Fore.RED + 'some red text')
        print('automatically back to default color again')

init(strip=None):
    Pass ``True`` or ``False`` to override whether ansi codes should be
    stripped from the output. The default behaviour is to strip if on Windows.

init(convert=None):
    Pass ``True`` or ``False`` to override whether to convert ansi codes in the
    output into win32 calls. The default behaviour is to convert if on Windows
    and output is to a tty (terminal).

init(wrap=True):
    On Windows, colorama works by replacing ``sys.stdout`` and ``sys.stderr``
    with proxy objects, which override the .write() method to do their work. If
    this wrapping causes you problems, then this can be disabled by passing
    ``init(wrap=False)``. The default behaviour is to wrap if autoreset or
    strip or convert are True.

    When wrapping is disabled, colored printing on non-Windows platforms will
    continue to work as normal. To do cross-platform colored output, you can
    use Colorama's ``AnsiToWin32`` proxy directly::

        import sys
        from colorama import init, AnsiToWin32
        init(wrap=False)
        stream = AnsiToWin32(sys.stderr).stream

        # Python 2
        print >>stream, Fore.BLUE + 'blue text on stderr'

        # Python 3
        print(Fore.BLUE + 'blue text on stderr', file=stream)


Status & Known Problems
=======================

I've personally only tested it on WinXP (CMD, Console2), Ubuntu
(gnome-terminal, xterm), and OSX.

Some presumably valid ANSI sequences aren't recognised (see details below)
but to my knowledge nobody has yet complained about this. Puzzling.

See outstanding issues and wishlist at:
http://code.google.com/p/colorama/issues/list

If anything doesn't work for you, or doesn't do what you expected or hoped for,
I'd love to hear about it on that issues list, would be delighted by patches,
and would be happy to grant commit access to anyone who submits a working patch
or two.


Recognised ANSI Sequences
=========================

ANSI sequences generally take the form:

    ESC [ <param> ; <param> ... <command>

Where <param> is an integer, and <command> is a single letter. Zero or more
params are passed to a <command>. If no params are passed, it is generally
synonymous with passing a single zero. No spaces exist in the sequence, they
have just been inserted here to make it easy to read.

The only ANSI sequences that colorama converts into win32 calls are::

    ESC [ 0 m       # reset all (colors and brightness)
    ESC [ 1 m       # bright
    ESC [ 2 m       # dim (looks same as normal brightness)
    ESC [ 22 m      # normal brightness

    # FOREGROUND:
    ESC [ 30 m      # black
    ESC [ 31 m      # red
    ESC [ 32 m      # green
    ESC [ 33 m      # yellow
    ESC [ 34 m      # blue
    ESC [ 35 m      # magenta
    ESC [ 36 m      # cyan
    ESC [ 37 m      # white
    ESC [ 39 m      # reset

    # BACKGROUND
    ESC [ 40 m      # black
    ESC [ 41 m      # red
    ESC [ 42 m      # green
    ESC [ 43 m      # yellow
    ESC [ 44 m      # blue
    ESC [ 45 m      # magenta
    ESC [ 46 m      # cyan
    ESC [ 47 m      # white
    ESC [ 49 m      # reset

    # cursor positioning
    ESC [ y;x H     # position cursor at x across, y down

    # clear the screen
    ESC [ mode J    # clear the screen. Only mode 2 (clear entire screen)
                    # is supported. It should be easy to add other modes,
                    # let me know if that would be useful.

Multiple numeric params to the 'm' command can be combined into a single
sequence, eg::

    ESC [ 36 ; 45 ; 1 m     # bright cyan text on magenta background

All other ANSI sequences of the form ``ESC [ <param> ; <param> ... <command>``
are silently stripped from the output on Windows.

Any other form of ANSI sequence, such as single-character codes or alternative
initial characters, are not recognised nor stripped. It would be cool to add
them though. Let me know if it would be useful for you, via the issues on
google code.


Development
===========

Help and fixes welcome! Ask Jonathan for commit rights, you'll get them.

Running tests requires:

- Michael Foord's 'mock' module to be installed.
- Tests are written using the 2010 era updates to 'unittest', and require to
  be run either using Python2.7 or greater, or else to have Michael Foord's
  'unittest2' module installed.

unittest2 test discovery doesn't work for colorama, so I use 'nose'::

    nosetests -s

The -s is required because 'nosetests' otherwise applies a proxy of its own to
stdout, which confuses the unit tests.


Contact
=======

Created by Jonathan Hartley, tartley@tartley.com


Thanks
======
| Ben Hoyt, for a magnificent fix under 64-bit Windows.
| Jesse@EmptySquare for submitting a fix for examples in the README.
| User 'jamessp', an observant documentation fix for cursor positioning.
| User 'vaal1239', Dave Mckee & Lackner Kristof for a tiny but much-needed Win7 fix.
| Julien Stuyck, for wisely suggesting Python3 compatible updates to README.
| Daniel Griffith for multiple fabulous patches.
| Oscar Lesta for valuable fix to stop ANSI chars being sent to non-tty output.
| Roger Binns, for many suggestions, valuable feedback, & bug reports.
| Tim Golden for thought and much appreciated feedback on the initial idea.