Print in terminal with colors?

Question

How can I output colored text to the terminal, in Python? What is the best Unicode symbol to represent a solid block?

Answer 1

This somewhat depends on what platform you are on. The most common way to do this is by printing ANSI escape sequences. For a simple example, here's some python code from the blender build scripts:

class bcolors:
    HEADER = '\033[95m'
    OKBLUE = '\033[94m'
    OKGREEN = '\033[92m'
    WARNING = '\033[93m'
    FAIL = '\033[91m'
    ENDC = '\033[0m'
    BOLD = '\033[1m'
    UNDERLINE = '\033[4m'

To use code like this, you can do something like

print bcolors.WARNING + "Warning: No active frommets remain. Continue?" 
      + bcolors.ENDC

This will work on unixes including OS X, linux and windows (provided you use ANSICON, or in Windows 10 provided you enable VT100 emulation). There are ansi codes for setting the color, moving the cursor, and more.

If you are going to get complicated with this (and it sounds like you are if you are writing a game), you should look into the "curses" module, which handles a lot of the complicated parts of this for you. The Python Curses HowTO is a good introduction.

If you are not using extended ASCII (i.e. not on a PC), you are stuck with the ascii characters below 127, and '#' or '@' is probably your best bet for a block. If you can ensure your terminal is using a IBM extended ascii character set, you have many more options. Characters 176, 177, 178 and 219 are the "block characters".

Some modern text-based programs, such as "Dwarf Fortress", emulate text mode in a graphical mode, and use images of the classic PC font. You can find some of these bitmaps that you can use on the Dwarf Fortress Wiki see (user-made tilesets).

The Text Mode Demo Contest has more resources for doing graphics in text mode.

Hmm.. I think got a little carried away on this answer. I am in the midst of planning an epic text-based adventure game, though. Good luck with your colored text!

Answer 2

I'm surprised no one has mentioned the Python termcolor module. Usage is pretty simple:

from termcolor import colored

print colored('hello', 'red'), colored('world', 'green')

Or in Python 3:

print(colored('hello', 'red'), colored('world', 'green'))

It may not be sophisticated enough, however, for game programming and the "colored blocks" that you want to do...

Answer 3

Print a string that starts a color/style, then the string, then end the color/style change with '\x1b[0m':

print('\x1b[6;30;42m' + 'Success!' + '\x1b[0m')

Get a table of format options for shell text with following code:

def print_format_table():
    """
    prints table of formatted text format options
    """
    for style in range(8):
        for fg in range(30,38):
            s1 = ''
            for bg in range(40,48):
                format = ';'.join([str(style), str(fg), str(bg)])
                s1 += '\x1b[%sm %s \x1b[0m' % (format, format)
            print(s1)
        print('\n')

print_format_table()

Light-on-dark example (complete)

Dark-on-light example (partial)

Answer 4

I ended up doing this, I felt it was cleanest:

formatters = {             
    'RED': '\033[91m',     
    'GREEN': '\033[92m',   
    'END': '\033[0m',      
}

print 'Master is currently {RED}red{END}!'.format(**formatters)
print 'Help make master {GREEN}green{END} again!'.format(**formatters)

Answer 5

https://raw.github.com/fabric/fabric/master/fabric/colors.py

"""
.. versionadded:: 0.9.2

Functions for wrapping strings in ANSI color codes.

Each function within this module returns the input string ``text``, wrapped
with ANSI color codes for the appropriate color.

For example, to print some text as green on supporting terminals::

    from fabric.colors import green

    print(green("This text is green!"))

Because these functions simply return modified strings, you can nest them::

    from fabric.colors import red, green

    print(red("This sentence is red, except for " + \
          green("these words, which are green") + "."))

If ``bold`` is set to ``True``, the ANSI flag for bolding will be flipped on
for that particular invocation, which usually shows up as a bold or brighter
version of the original color on most terminals.
"""


def _wrap_with(code):

    def inner(text, bold=False):
        c = code
        if bold:
            c = "1;%s" % c
        return "\033[%sm%s\033[0m" % (c, text)
    return inner

red = _wrap_with('31')
green = _wrap_with('32')
yellow = _wrap_with('33')
blue = _wrap_with('34')
magenta = _wrap_with('35')
cyan = _wrap_with('36')
white = _wrap_with('37')

Answer 6

Define a string that starts a color and a string that ends the color, then print your text with the start string at the front and the end string at the end.

CRED = '\033[91m'
CEND = '\033[0m'
print(CRED + "Error, does not compute!" + CEND)

This produces the following in bash, in urxvt with a Zenburn-style color scheme:

Through experemintation, we can get more colors:

Note: \33[5m and \33[6m are blinking.

This way we can create a full color collection:

CEND      = '\33[0m'
CBOLD     = '\33[1m'
CITALIC   = '\33[3m'
CURL      = '\33[4m'
CBLINK    = '\33[5m'
CBLINK2   = '\33[6m'
CSELECTED = '\33[7m'

CBLACK  = '\33[30m'
CRED    = '\33[31m'
CGREEN  = '\33[32m'
CYELLOW = '\33[33m'
CBLUE   = '\33[34m'
CVIOLET = '\33[35m'
CBEIGE  = '\33[36m'
CWHITE  = '\33[37m'

CBLACKBG  = '\33[40m'
CREDBG    = '\33[41m'
CGREENBG  = '\33[42m'
CYELLOWBG = '\33[43m'
CBLUEBG   = '\33[44m'
CVIOLETBG = '\33[45m'
CBEIGEBG  = '\33[46m'
CWHITEBG  = '\33[47m'

CGREY    = '\33[90m'
CRED2    = '\33[91m'
CGREEN2  = '\33[92m'
CYELLOW2 = '\33[93m'
CBLUE2   = '\33[94m'
CVIOLET2 = '\33[95m'
CBEIGE2  = '\33[96m'
CWHITE2  = '\33[97m'

CGREYBG    = '\33[100m'
CREDBG2    = '\33[101m'
CGREENBG2  = '\33[102m'
CYELLOWBG2 = '\33[103m'
CBLUEBG2   = '\33[104m'
CVIOLETBG2 = '\33[105m'
CBEIGEBG2  = '\33[106m'
CWHITEBG2  = '\33[107m'

Here is the code to generate the test:

x = 0
for i in range(24):
  colors = ""
  for j in range(5):
    code = str(x+j)
    colors = colors + "\33[" + code + "m\\33[" + code + "m\033[0m "
  print(colors)
  x=x+5