colorama 0.4.6rc1

Initialisation

If the only thing you want from Colorama is to get ANSI escapes to work on Windows, then run:

from colorama import just_fix_windows_console
just_fix_windows_console()

If you’re on a recent version of Windows 10 or better, and your stdout/stderr are pointing to a Windows console, then this will flip the magic configuration switch to enable Windows’ built-in ANSI support.

If you’re on an older version of Windows, and your stdout/stderr are pointing to a Windows console, then this will wrap sys.stdout and/or sys.stderr in a magic file object that intercepts ANSI escape sequences and issues the appropriate Win32 calls to emulate them.

In all other circumstances, it does nothing whatsoever. Basically the idea is that this makes Windows act like Unix with respect to ANSI escape handling.

It’s safe to call this function multiple times. It’s safe to call this function on non-Windows platforms, but it won’t do anything. It’s safe to call this function when one or both of your stdout/stderr are redirected to a file – it won’t do anything to those streams.

Alternatively, you can use the older interface with more features (but also more potential footguns):

from colorama import init
init()

This does the same thing as just_fix_windows_console, except for the following differences:

• It’s not safe to call init multiple times; you can end up with multiple layers of wrapping and broken ANSI support.

• Colorama will apply a heuristic to guess whether stdout/stderr support ANSI, and if it thinks they don’t, then it will wrap sys.stdout and sys.stderr in a magic file object that strips out ANSI escape sequences before printing them. This happens on all platforms, and can be convenient if you want to write your code to emit ANSI escape sequences unconditionally, and let Colorama decide whether they should actually be output. But note that Colorama’s heuristic is not particularly clever.

• init also accepts explicit keyword args to enable/disable various functionality – see below.

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).

Most users should depend on colorama >= 0.4.6, and use just_fix_windows_console. The old init interface will be supported indefinitely for backwards compatibility, but we don’t plan to fix any issues with it, also for backwards compatibility.

Colored Output

Cross-platform printing of colored text can then be done using Colorama’s constant shorthand for ANSI escape sequences. These are deliberately rudimentary, see below.

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 the fabulous Blessings, or the incredible _Rich.

If you wish Colorama’s Fore, Back and Style constants were more capable, then consider using one of the above highly capable libraries to generate colors, etc, and use Colorama just for its primary purpose: to convert those ANSI sequences to also work on Windows:

SIMILARLY, do not send PRs adding the generation of new ANSI types to Colorama. We are only interested in converting ANSI codes to win32 API calls, not shortcuts like the above to generate ANSI characters.

from colorama import just_fix_windows_console
from termcolor import colored

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

# 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.

These are fairly well supported, but not part of the standard:

Fore: LIGHTBLACK_EX, LIGHTRED_EX, LIGHTGREEN_EX, LIGHTYELLOW_EX, LIGHTBLUE_EX, LIGHTMAGENTA_EX, LIGHTCYAN_EX, LIGHTWHITE_EX
Back: LIGHTBLACK_EX, LIGHTRED_EX, LIGHTGREEN_EX, LIGHTYELLOW_EX, LIGHTBLUE_EX, LIGHTMAGENTA_EX, LIGHTCYAN_EX, LIGHTWHITE_EX

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.