Print Git-like diff of arbitrary 2 strings in Python

diff.py

import difflib


def diff(a: str, b: str) -> None:
    line_color = {"+": 32, "-": 31}

    diffs = difflib.ndiff(a.splitlines(keepends=True), b.splitlines(keepends=True))
    diff_list = list(diffs)
    styled: list[str] = []
    for prev, next in zip(diff_list, diff_list[1:] + [""]):
        color = line_color.get(prev[0], 0)
        match prev[0]:
            case " ":
                styled.append(prev)
            case "+" | "-":
                index = [i for i, c in enumerate(next) if c == "^"]
                _prev = list(prev)
                for idx in index:
                    _prev[idx] = f"\x1b[97;{color+10};1m{_prev[idx]}\x1b[0;{color}m"
                styled.append(f'\x1b[{color}m{"".join(_prev)}\x1b[0m')
            case "?":
                continue
    print("".join(styled))

example.ipynb

{
 "cells": [
  {
   "cell_type": "code",
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   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "  foo\n",
      "\u001b[31m- b\u001b[97;41;1ma\u001b[0;31mr\n",
      "\u001b[0m\u001b[32m+ b\u001b[97;42;1mb\u001b[0;32mr\n",
      "\u001b[0m\u001b[31m- baz\n",
      "\u001b[0m\u001b[32m+ quux\n",
      "\u001b[0m\u001b[31m- ho\u001b[97;41;1mg\u001b[0;31meho\u001b[97;41;1mg\u001b[0;31me\n",
      "\u001b[0m\u001b[32m+ ho\u001b[97;42;1md\u001b[0;32meho\u001b[97;42;1md\u001b[0;32me\n",
      "\u001b[0m\n"
     ]
    }
   ],
   "source": [
    "import difflib\n",
    "\n",
    "\n",
    "def diff(a: str, b: str) -> None:\n",
    "    line_color = {\"+\": 32, \"-\": 31}\n",
    "\n",
    "    diffs = difflib.ndiff(a.splitlines(keepends=True), b.splitlines(keepends=True))\n",
    "    diff_list = list(diffs)\n",
    "    styled: list[str] = []\n",
    "    for prev, next in zip(diff_list, diff_list[1:] + [\"\"]):\n",
    "        color = line_color.get(prev[0], 0)\n",
    "        match prev[0]:\n",
    "            case \" \":\n",
    "                styled.append(prev)\n",
    "            case \"+\" | \"-\":\n",
    "                index = [i for i, c in enumerate(next) if c == \"^\"]\n",
    "                _prev = list(prev)\n",
    "                for idx in index:\n",
    "                    _prev[idx] = f\"\\x1b[97;{color+10};1m{_prev[idx]}\\x1b[0;{color}m\"\n",
    "                styled.append(f'\\x1b[{color}m{\"\".join(_prev)}\\x1b[0m')\n",
    "            case \"?\":\n",
    "                continue\n",
    "    print(\"\".join(styled))\n",
    "\n",
    "\n",
    "a = \"\"\"\\\n",
    "foo\n",
    "bar\n",
    "baz\n",
    "hogehoge\n",
    "\"\"\"\n",
    "\n",
    "b = \"\"\"\\\n",
    "foo\n",
    "bbr\n",
    "quux\n",
    "hodehode\n",
    "\"\"\"\n",
    "\n",
    "diff(a, b)"
   ]
  }
 ],
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