colors.py: show all kinds of terminal colors at a glance

colors.py

#!/usr/bin/python3

from functools import partial

def colors16():
  for bold in [0, 1]:
    for i in range(30, 38):
      for j in range(40, 48):
        print(f'\x1b[{bold};{i};{j}m {bold};{i};{j} |\x1b[0m', end='')
      print()
    print()

  for bold in [0, 1]:
    for i in range(90, 98):
      for j in range(100, 108):
        print(f'\x1b[{bold};{i};{j}m {bold};{i};{j} |\x1b[0m', end='')
      print()
    print()

def color1(c, n=0):
  print(f'\x1b[{n};38;5;{c}m{c:4}\x1b[0m', end='')

def color1_sep(c):
  if (c - 15) % 18 == 0:
    print()

def color2(c):
  print(f'\x1b[48;5;{c}m  \x1b[0m', end='')

def color2_sep(c):
  if (c - 15) % 36 == 0:
    print()
  elif (c - 15) % 6 == 0:
    print(' ', end='')

def colors256(color, sepfunc):
  for i in range(0, 8):
    color(i)
  print()
  for i in range(8, 16):
    color(i)
  print('\n')

  for i in range(16, 232):
    color(i)
    sepfunc(i)
  print()

  for i in range(232, 256):
    color(i)
  print('\n')

def colors_gradient():
  s= '/\\' * 40
  for col in range(0, 77):
    r = 255 - col * 255 // 76
    g = col * 510 // 76
    b = col * 255 // 76
    if g > 255:
      g = 510 - g
    print(f'\x1b[48;2;{r};{g};{b}m\x1b[38;2;{255-r};{255-g};{255-b}m{s[col]}\x1b[0m', end='')
  print()

def other_attributes():
  for i in range(0, 10):
    print(f' \x1b[{i}mSGR {i:2}\x1b[m', end=' ')
  print(' \x1b[53mSGR 53\x1b[m', end=' ') # overline
  print('\n')
  # https://askubuntu.com/a/985386/235132
  for i in range(1, 6):
    print(f' \x1b[4:{i}mSGR 4:{i}\x1b[m', end=' ')
  print(' \x1b[21mSGR 21\x1b[m', end=' ')

  print(' \x1b[4:3m\x1b[58;2;135;0;255mtruecolor underline\x1b[59m\x1b[4:0m', end=' ')
  print(' \x1b]8;;https://askubuntu.com/a/985386/235132\x1b\\hyperlink\x1b]8;;\x1b\\')

if __name__ == '__main__':
  print('basic 16 colors, foreground & background:\n')
  colors16()

  print('256 colors:\n')
  colors256(color1, color1_sep)

  print('256 colors, bold:\n')
  colors256(partial(color1, n=1), color1_sep)

  print('256 colors, dim:\n')
  colors256(partial(color1, n=2), color1_sep)

  print('256 colors, bold dim:\n')
  colors256(partial(color1, n='1;2'), color1_sep)

  print('256 colors, solid background:\n')
  colors256(color2, color2_sep)

  print('true colors gradient:\n')
  colors_gradient()

  print('other attributes:\n')
  other_attributes()