DOC: more detailed section about ANSI colors

spatialaudio · Feb 2, 2016 · a2cc323 · a2cc323
1 parent 14fbcc4
commit a2cc323
Showing 1 changed file with 111 additions and 26 deletions.
diff --git a/doc/code-cells.ipynb b/doc/code-cells.ipynb
@@ -115,31 +115,6 @@
     "\"I'm the 'normal' output\""
    ]
   },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## ANSI Colors\n",
-    "\n",
-    "The standard output and standard error streams may contain [ANSI escape sequences](https://en.wikipedia.org/wiki/ANSI_escape_code) to change the text and background colors."
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [],
-   "source": [
-    "print('BEWARE: \\x1b[1;33;41mugly colors\\x1b[0m!', file=sys.stderr, flush=True)\n",
-    "for bg in range(40, 48):\n",
-    "    for fg in range(30, 38):\n",
-    "        print('\\x1b[{fg};{bg}mX\\x1b[0m'.format(**locals()), end='')\n",
-    "        print('\\x1b[1;{fg};{bg}mX\\x1b[0m'.format(**locals()), end='')\n",
-    "    print()"
-   ]
-  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -316,6 +291,13 @@
     "\\end{equation}"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### YouTube Videos"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,
@@ -326,10 +308,113 @@
    "source": [
     "YouTubeVideo('iV2ViNJFZC8')"
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## ANSI Colors\n",
+    "\n",
+    "The standard output and standard error streams may contain [ANSI escape sequences](https://en.wikipedia.org/wiki/ANSI_escape_code) to change the text and background colors."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "print('BEWARE: \\x1b[1;33;41mugly colors\\x1b[m!', file=sys.stderr, flush=True)\n",
+    "print('ABC\\x1b[43mDEF\\x1b[35mGHI\\x1b[1mJKL\\x1b[49mMNO\\x1b[39mPQR\\x1b[22mSTU')"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "The following code showing the 8 basic ANSI colors is based on http://tldp.org/HOWTO/Bash-Prompt-HOWTO/x329.html.\n",
+    "Note that Jupyter does not switch to a brighter color for bold text."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "text = ' XYZ '\n",
+    "formatstring = '\\x1b[{}m' + text + '\\x1b[m'\n",
+    "\n",
+    "print(' ' * 6 + ' ' * len(text) +\n",
+    "      ''.join('{:^{}}'.format(bg, len(text)) for bg in range(40, 48)))\n",
+    "for fg in range(30, 38):\n",
+    "    for bold in False, True:\n",
+    "        fg_code = ('1;' if bold else '') + str(fg)\n",
+    "        print(' {:>4} '.format(fg_code) + formatstring.format(fg_code) +\n",
+    "              ''.join(formatstring.format(fg_code + ';' + str(bg))\n",
+    "                      for bg in range(40, 48)))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "ANSI also supports a set of 256 indexed colors.\n",
+    "The following code showing all of them is based on http://bitmote.com/index.php?post/2012/11/19/Using-ANSI-Color-Codes-to-Colorize-Your-Bash-Prompt-on-Linux."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "formatstring = '\\x1b[38;5;{0};48;5;{0}mX\\x1b[1mX\\x1b[m'\n",
+    "\n",
+    "print('  + ' + ''.join('{:2}'.format(i) for i in range(36)))\n",
+    "print('  0 ' + ''.join(formatstring.format(i) for i in range(16)))\n",
+    "for i in range(7):\n",
+    "    i = i * 36 + 16\n",
+    "    print('{:3} '.format(i) + ''.join(formatstring.format(i + j)\n",
+    "                                      for j in range(36) if i + j < 256))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "You can even use 24-bit RGB colors:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "start = 255, 0, 0\n",
+    "end = 0, 0, 255\n",
+    "length = 79\n",
+    "out = []\n",
+    "\n",
+    "for i in range(length):\n",
+    "    rgb = [start[c] + int(i * (end[c] - start[c]) / length) for c in range(3)]\n",
+    "    out.append('\\x1b['\n",
+    "               '38;2;{rgb[2]};{rgb[1]};{rgb[0]};'\n",
+    "               '48;2;{rgb[0]};{rgb[1]};{rgb[2]}mX\\x1b[m'.format(rgb=rgb))\n",
+    "print(''.join(out))"
+   ]
   }
  ],
  "metadata": {
-  "celltoolbar": "Raw Cell Format",
   "kernelspec": {
    "display_name": "Python 3",
    "language": "python",