Ch07.정규표현식, 파트 II.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# 7.2 태그를 남기지 않는 그룹"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 7.2.2 태깅 문제 고치기"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "12,000\n",
      "100\n",
      "53.12\n"
     ]
    }
   ],
   "source": [
    "import re\n",
    "\n",
    "pat = r'\\d{1,3}(?:,\\d{3})*(?:\\.\\d*)?\\b'\n",
    "s = '12,000 monkeys on 100 typewriters for 53.12 days.'\n",
    "lst = re.findall(pat, s)\n",
    "for item in lst:\n",
    "    print(item)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# 7.3 탐욕적 일치 vs 게으른 일치"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "<h1>This is an HTML heading.<\\h1>\n"
     ]
    }
   ],
   "source": [
    "import re\n",
    "\n",
    "pat = r'<.*>'  # 탐욕적 일치\n",
    "the_line = '<h1>This is an HTML heading.<\\h1>'\n",
    "m = re.match(pat, the_line)\n",
    "print(m.group())"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "<h1>\n"
     ]
    }
   ],
   "source": [
    "pat = r'<.*?>' # 게으른 일치\n",
    "the_line = '<h1>This is an HTML heading.<\\h1>'\n",
    "m = re.match(pat, the_line)\n",
    "print(m.group())"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [],
   "source": [
    "s = r'''<h1>This is the first heading<\\h1>\n",
    "<h1>This is the second heading<\\h1>\n",
    "<b>This is in bold<\\b>\n",
    "'''"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "There are 6 tags.\n"
     ]
    }
   ],
   "source": [
    "pat = r'<.*?>'  # 게으른 일치\n",
    "lst = re.findall(pat, s, flags=re.DOTALL)\n",
    "print('There are', len(lst), 'tags.')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "There are 1 tags.\n"
     ]
    }
   ],
   "source": [
    "pat = r'<.*>'  # 탐욕적 일치\n",
    "lst = re.findall(pat, s, flags=re.DOTALL)\n",
    "print('There are', len(lst), 'tags.')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [],
   "source": [
    "s = '''Here is a single sentence. Here is\n",
    "another sentence, ending in a period. And\n",
    "here is yet another.\n",
    "'''"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "There are  3 sentences.\n"
     ]
    }
   ],
   "source": [
    "pat = r'.*?[.?!]'\n",
    "lst = re.findall(pat, s, flags=re.DOTALL)\n",
    "print('There are ', len(lst), 'sentences.')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# 7.4 전방탐색 기능"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "s = '''See the U.S.A. today. It's right here, not\n",
    "a world away. Average temp. is 66.5.'''"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "-> See the U.S.A. today.\n",
      "-> It's right here, not\n",
      "a world away.\n",
      "-> Average temp. is 66.5.\n"
     ]
    }
   ],
   "source": [
    "import re\n",
    "\n",
    "pat = r'[A-Z].*?[.!?](?= [A-Z]|$)'\n",
    "m = re.findall(pat, s, flags=re.DOTALL | re.MULTILINE)\n",
    "\n",
    "for i in m:\n",
    "    print('->', i)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "-> See the U.S.A. today. I\n",
      "-> \n"
     ]
    }
   ],
   "source": [
    "pat = r'[A-Z].*?[.!?] [A-Z]|$'\n",
    "m = re.findall(pat, s, flags=re.DOTALL)\n",
    "for i in m:\n",
    "    print('->', i)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# 7.5 다중 패턴 확인하기(전방탐색)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [],
   "source": [
    "pat1 = r'(\\w|[!@#$%^&*+-]){8,12}$'\n",
    "pat2 = r'(?=.*[a-zA-Z])'\n",
    "pat3 = r'(?=.*\\d)'\n",
    "pat4 = r'(?=.*[!@#$%^&*+-])'\n",
    "\n",
    "pat = pat2 + pat3 + pat4 + pat1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "It passed the test!\n"
     ]
    }
   ],
   "source": [
    "import re\n",
    "\n",
    "passwd = 'HenryThe5!'\n",
    "if re.match(pat, passwd):\n",
    "    print('It passed the test!')\n",
    "else:\n",
    "    print('Insufficiently strong password')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# 7.6 부정적 전방탐색"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['abc']\n"
     ]
    }
   ],
   "source": [
    "import re\n",
    "pat = r'abc(?!abc)'\n",
    "s = 'The magic of abcabc.'\n",
    "m = re.findall(pat, s)\n",
    "print(m)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['ABC']\n"
     ]
    }
   ],
   "source": [
    "pat = r'abc(?!abc)'\n",
    "s = 'The magic of abcABC.'\n",
    "m = re.findall(pat, s, flags=re.I)\n",
    "print(m)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "s = '''See the U.S.A. today. It's right here, not\n",
    "a world away. Average temp. is 70.5.'''"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "-> See the U.S.A. today.\n",
      "-> It's right here, not\n",
      "a world away.\n",
      "-> Average temp. is 70.5.\n"
     ]
    }
   ],
   "source": [
    "pat = r'[A-Z].*?[.!?](?! [a-z0-9]|\\w)'\n",
    "m = re.findall(pat, s, flags=re.DOTALL)\n",
    "for i in m:\n",
    "    print('->', i)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "-> See the U.S.A. today.\n",
      "-> It's right here, nota world away.\n",
      "-> Average temp. is 70.5.\n"
     ]
    }
   ],
   "source": [
    "s = re.sub(r'\\n', '', s)\n",
    "pat = r'[A-Z].*?[.!?](?! [a-z0-9]|\\w)'\n",
    "m = re.findall(pat, s, flags=re.DOTALL)\n",
    "for i in m:\n",
    "    print('->', i)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# 7.7 명명 그룹"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [],
   "source": [
    "pat = r'(?P<first>\\w+) (?P<last>\\w+)'"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [],
   "source": [
    "import re\n",
    "s = 'Jane Austen'\n",
    "m = re.match(pat, s)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "first name =  Jane\n",
      "last name =  Austen\n"
     ]
    }
   ],
   "source": [
    "print('first name = ', m.group('first'))\n",
    "print('last name = ', m.group('last'))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Austen, Jane\n"
     ]
    }
   ],
   "source": [
    "print(m.group('last') + ', ' + m.group('first'))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [],
   "source": [
    "pat = r'(?P<first>\\w+) (?P<mid>\\w\\. )?(?P<last>\\w+)'"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [],
   "source": [
    "def recorg_name(in_s):\n",
    "    m = re.match(pat, in_s)\n",
    "    s = m.group('last') + ', ' + m.group('first')\n",
    "    if m.group('mid'):\n",
    "        s += ' ' + m.group('mid')\n",
    "    return s"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [],
   "source": [
    "pat = r'(?P<word>\\w+) (?P=word)'\n",
    "m = re.search(pat, 'The the dog.', flags=re.I)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# 7.8 re.split 함수"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {},
   "outputs": [],
   "source": [
    "pat = r', *| +'"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['3', '5', '7', '8', '10', '11']\n"
     ]
    }
   ],
   "source": [
    "import re\n",
    "lst = re.split(pat, '3, 5 7 8, 10, 11')\n",
    "print(lst)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "3 2 * 2 15 * + 4 +\n"
     ]
    }
   ],
   "source": [
    "s = '3 2 * 2 15 * + 4 +'\n",
    "toks = re.split(pat, s)\n",
    "print(s)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# 7.9 스캐너 클래스와 RPN 프로젝트"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [],
   "source": [
    "import re\n",
    "\n",
    "def sc_oper(scanner, tok): return tok\n",
    "def sc_int(scanner, tok): return int(tok)\n",
    "def sc_float(scanner, tok): return float(tok)\n",
    "\n",
    "scanner = re.Scanner([\n",
    "    (r'[*+/-]', sc_oper),\n",
    "    (r'\\d+\\.\\d*', sc_float),\n",
    "    (r'\\d+', sc_int),\n",
    "    (r'\\s+', None)\n",
    "])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "([3, 3, '+'], '')\n"
     ]
    }
   ],
   "source": [
    "print(scanner.scan('3 3+'))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "([32, 6.67, '+', 10, 5, '-', '*'], '')\n"
     ]
    }
   ],
   "source": [
    "print(scanner.scan('32 6.67+ 10 5- *'))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# 7.10 RPN: 스캐너로 더 많은 작업 수행하기"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [],
   "source": [
    "scanner = re.Scanner([\n",
    "    (r'[*+/-]', lambda s, t: bin_op(t)),\n",
    "    (r'\\d+\\.\\d*', lambda s, t: the_stk.append(float(t))),\n",
    "    (r'\\d+', lambda s, t: the_stk.append(int(t))),\n",
    "    (r'\\s+', None)\n",
    "])\n",
    "\n",
    "def bin_op(tok):\n",
    "    op2, op1 = the_stk.pop(), the_stk.pop()\n",
    "    if tok == '+':\n",
    "        the_stk.append(op1 + op2)\n",
    "    elif tok == '*':\n",
    "        the_stk.append(op1 * op2)\n",
    "    elif tok == '/':\n",
    "        the_stk.append(op1 / op2)\n",
    "    elif tok == '-':\n",
    "        the_stk.append(op1 - op2)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Enter RPN string: ddd\n",
      "Unrecognized input: ddd\n"
     ]
    }
   ],
   "source": [
    "import re\n",
    "\n",
    "the_stk = []\n",
    "\n",
    "scanner = re.Scanner([\n",
    "    (r'[*+/-]', lambda s, t: bin_op(t)),\n",
    "    (r'\\d+\\.\\d*', lambda s, t: the_stk.append(float(t))),\n",
    "    (r'\\d+', lambda s, t: the_stk.append(int(t))),\n",
    "    (r'\\s+', None)\n",
    "])\n",
    "\n",
    "def bin_op(tok):\n",
    "    op2, op1 = the_stk.pop(), the_stk.pop()\n",
    "    if tok == '+':\n",
    "        the_stk.append(op1 + op2)\n",
    "    elif tok == '*':\n",
    "        the_stk.append(op1 * op2)\n",
    "    elif tok == '/':\n",
    "        the_stk.append(op1 / op2)\n",
    "    elif tok == '-':\n",
    "        the_stk.append(op1 - op2)\n",
    "        \n",
    "def main():\n",
    "    input_str = input('Enter RPN string: ')\n",
    "    tokens, unknown = scanner.scan(input_str)\n",
    "    if unknown:\n",
    "        print('Unrecognized input:', unknown)\n",
    "    else:\n",
    "        print('Answer is', the_stk.pop())\n",
    "        \n",
    "main()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Enter RPN string: 5 6+ 1.1/\n",
      "Answer is 10.0\n"
     ]
    }
   ],
   "source": [
    "import re\n",
    "import operator\n",
    "\n",
    "the_stk = []\n",
    "\n",
    "scanner = re.Scanner([\n",
    "    (r'[+]', lambda s, t: bin_op(operator.add)),\n",
    "    (r'[*]', lambda s, t: bin_op(operator.mul)),\n",
    "    (r'[-]', lambda s, t: bin_op(operator.sub)),\n",
    "    (r'[/]', lambda s, t: bin_op(operator.truediv)),\n",
    "    (r'\\d+\\.\\d*', lambda s, t: the_stk.append(float(t))),\n",
    "    (r'\\d+', lambda s, t: the_stk.append(int(t))),\n",
    "    (r'\\s+', None)\n",
    "])\n",
    "\n",
    "def bin_op(oper):\n",
    "    op2, op1 = the_stk.pop(), the_stk.pop()\n",
    "    the_stk.append(oper(op1, op2))\n",
    "        \n",
    "def main():\n",
    "    input_str = input('Enter RPN string: ')\n",
    "    tokens, unknown = scanner.scan(input_str)\n",
    "    if unknown:\n",
    "        print('Unrecognized input:', unknown)\n",
    "    else:\n",
    "        print('Answer is', the_stk.pop())\n",
    "        \n",
    "main()"
   ]
  }
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