cols 0.0.1

Cross-platform colored terminal text.

Colorama

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

PyPI for releases · Github for source · Colorama for enterprise on Tidelift

If you find Colorama useful, please to the authors. Thank you!

Installation

pip install colorama
# or
conda install -c anaconda colorama

Description

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 would appear as gobbledygook in the output), and converting them into the appropriate win32 calls to modify the state of the terminal. On other platforms, Colorama does nothing.

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 print some colored text using ANSI sequences. Compare their output under Gnome-terminal’s built in ANSI handling, versus on Windows Command-Prompt using Colorama:

These screenshots show that, on Windows, Colorama does not support ANSI ‘dim text’; it looks the same as ‘normal text’.

Usage

Initialisation

Applications should initialise Colorama using:

from colorama import init
init()

On Windows, calling init() will filter ANSI escape sequences out of any text sent to stdout or stderr, and replace them with equivalent Win32 calls.

On other platforms, calling init() has no effect (unless you request other optional functionality; see “Init Keyword Args”, below). By design, this permits applications to 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 resume using Colorama again, call reinit(); it is cheaper than calling init() again (but does the same thing).

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(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[39m') # and reset to default color

…or, Colorama can be used in conjunction with existing ANSI libraries such as the venerable Termcolor or the fabulous Blessings. This is highly recommended for anything more than trivial coloring:

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 or if output is redirected (not a tty).

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)

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 been inserted here simply to read more easily.

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
ESC [ y;x f     # position cursor at x across, y down
ESC [ n A       # move cursor n lines up
ESC [ n B       # move cursor n lines down
ESC [ n C       # move cursor n characters forward
ESC [ n D       # move cursor n characters backward

# clear the screen
ESC [ mode J    # clear the screen

# clear the line
ESC [ mode K    # clear the line

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

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 or stripped. It would be cool to add them though. Let me know if it would be useful for you, via the Issues on GitHub.

Status & Known Problems

I’ve personally only tested it on Windows XP (CMD, Console2), Ubuntu (gnome-terminal, xterm), and OS X.

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 wish-list: https://github.com/tartley/colorama/issues

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.

License

Copyright Jonathan Hartley & Arnon Yaari, 2013-2020. BSD 3-Clause license; see LICENSE file.

Development

Help and fixes welcome!

Tested on CPython 2.7, 3.5, 3.6, 3.7 and 3.8.

No requirements other than the standard library. Development requirements are captured in requirements-dev.txt.

To create and populate a virtual environment:

./bootstrap.ps1 # Windows
make bootstrap # Linux

To run tests:

./test.ps1 # Windows
make test # Linux

If you use nose to run the tests, you must pass the -s flag; otherwise, nosetests applies its own proxy to stdout, which confuses the unit tests.

To build a local wheel file:

./build.ps1 # Windows
make build # Linux

To test the wheel, (upload to test PyPI, then ‘pip install’ & use it):

./test-release.ps1 # Windows
make test-release # Linux

To upload the wheel to PyPI:

./release.ps1 # Windows
make release # Linux

To clean all generated files, builds, virtualenv:

./clean.ps1 # Windows
make clean # Linux

Professional support

Professional support for colorama is available as part of the Tidelift Subscription. Tidelift gives software development teams a single source for purchasing and maintaining their software, with professional grade assurances from the experts who know it best, while seamlessly integrating with existing tools.

Thanks

• Marc Schlaich (schlamar) for a setup.py fix for Python2.5.

• Marc Abramowitz, reported & fixed a crash on exit with closed stdout, providing a solution to issue #7’s setuptools/distutils debate, and other fixes.

• User ‘eryksun’, for guidance on correctly instantiating ctypes.windll.

• Matthew McCormick for politely pointing out a longstanding crash on non-Win.

• Ben Hoyt, for a magnificent fix under 64-bit Windows.

• Jesse at Empty Square 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 a 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.

• User ‘Zearin’ for updates to the README file.

• John Szakmeister for adding support for light colors

• Charles Merriam for adding documentation to demos

• Jurko for a fix on 64-bit Windows CPython2.5 w/o ctypes

• Florian Bruhin for a fix when stdout or stderr are None

• Thomas Weininger for fixing ValueError on Windows

• Remi Rampin for better Github integration and fixes to the README file

• Simeon Visser for closing a file handle using ‘with’ and updating classifiers to include Python 3.3 and 3.4

• Andy Neff for fixing RESET of LIGHT_EX colors.

• Jonathan Hartley for the initial idea and implementation.