Python2019/labs02/Podstawy cz. 2.ipynb

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    "# Podstawy Pythona: cz. 3\n",
    "\n",
    " \n",
    "\n",
    "##  27 stycznia 2019"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
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   "source": [
    "## Co już było?\n",
    " * podstawowe typy danych\n",
    " * operacje arytmetyczne\n",
    " * wyświtlanie na ekran\n",
    " * pętla `for`, instrukcja `if`\n",
    " * listy i słowniki"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
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   "source": [
    "## Funkcje\n",
    "\n",
    " * znamy kilka funkcji, np. print, len\n",
    " * funckje w pythonie nie odbiegają od funkcji w innych językach\n",
    " * może istnieć tylko 1 funkcja o danej nazwie"
   ]
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  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {
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   "outputs": [],
   "source": [
    "def nazwa_funkcji(argument1, argument2, argument3):\n",
    "    # instrukcje do wykoniania\n",
    "    return wartosc"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {
    "slideshow": {
     "slide_type": "slide"
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   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "True\n"
     ]
    }
   ],
   "source": [
    "def is_greater_than_5(x):\n",
    "    if x > 5:\n",
    "        return True\n",
    "    else:\n",
    "        return False\n",
    "    \n",
    "print(is_greater_than_5(10))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {
    "slideshow": {
     "slide_type": "slide"
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   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "8.0\n"
     ]
    }
   ],
   "source": [
    "def srednia(lista):\n",
    "    s = 0\n",
    "    for item in lista:\n",
    "        s += item\n",
    "    return s / len(lista) \n",
    "\n",
    "print(srednia([7,8,9]))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {
    "slideshow": {
     "slide_type": "slide"
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   "outputs": [],
   "source": [
    "def count(lista, item):\n",
    "    l = 0\n",
    "    for i in lista:\n",
    "        if i == item:\n",
    "            l += 1\n",
    "    return l"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {
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   "outputs": [
    {
     "data": {
      "text/plain": [
       "3"
      ]
     },
     "execution_count": 12,
     "metadata": {},
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   ],
   "source": [
    "count([3,3,3,4], 3)\n",
    "count(lista=[3,3,3,4], item=3)\n",
    "count(item=3, lista=[3,3,3,4])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {
    "slideshow": {
     "slide_type": "slide"
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   "outputs": [],
   "source": [
    "def is_grater_than(x, y=0):\n",
    "    if x > y:\n",
    "        return True\n",
    "    else:\n",
    "        return False"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {
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     "slide_type": "slide"
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   "outputs": [
    {
     "data": {
      "text/plain": [
       "False"
      ]
     },
     "execution_count": 16,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "is_grater_than(5)\n",
    "is_grater_than(x=5)\n",
    "is_grater_than(5, 0)\n",
    "is_grater_than(5, 6)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "metadata": {
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     "slide_type": "slide"
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   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['a', 'b', 'c', 'd']\n"
     ]
    }
   ],
   "source": [
    "def alfaRange(x, y):\n",
    "    for i in range(ord(x), ord(y)):\n",
    "        yield chr(i)\n",
    "print(list(alfaRange('a', 'e')))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
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   },
   "source": [
    "## Operacje na plikach"
   ]
  },
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   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "slideshow": {
     "slide_type": "slide"
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   "outputs": [],
   "source": [
    "plik = open(\"haslo.txt\", 'r')\n",
    "for linia in plik.readlines():\n",
    "    print(linia.strip())\n",
    "print(\">>\")\n",
    "plik.close()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {
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     "slide_type": "slide"
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   "outputs": [
    {
     "ename": "FileNotFoundError",
     "evalue": "[Errno 2] No such file or directory: 'haslo.txt'",
     "output_type": "error",
     "traceback": [
      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[0;31mFileNotFoundError\u001b[0m                         Traceback (most recent call last)",
      "\u001b[0;32m<ipython-input-18-c98a6e23ed86>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0;32mwith\u001b[0m \u001b[0mopen\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m\"haslo.txt\"\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m'r'\u001b[0m\u001b[0;34m)\u001b[0m \u001b[0;32mas\u001b[0m \u001b[0mplik\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m      2\u001b[0m     \u001b[0;32mfor\u001b[0m \u001b[0mlinia\u001b[0m \u001b[0;32min\u001b[0m \u001b[0mplik\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mreadlines\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m      3\u001b[0m         \u001b[0mprint\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mlinia\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
      "\u001b[0;31mFileNotFoundError\u001b[0m: [Errno 2] No such file or directory: 'haslo.txt'"
     ]
    }
   ],
   "source": [
    "with open(\"haslo.txt\", 'r') as plik:\n",
    "    for linia in plik.readlines():\n",
    "        print(linia)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 19,
   "metadata": {
    "slideshow": {
     "slide_type": "slide"
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   "outputs": [],
   "source": [
    "with open(\"haslo2.txt\", 'w') as plik:\n",
    "    for word in ('corect', 'horse', 'battery', 'staple'):\n",
    "        plik.write(word)\n",
    "    plik.write('\\n')\n",
    "with open(\"haslo2.txt\", 'w+') as plik:\n",
    "    plik.writelines([' '.join(('corect', 'horse', 'battery', 'staple'))])"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "slideshow": {
     "slide_type": "slide"
    }
   },
   "source": [
    "## Korzystanie z bibliotek"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 20,
   "metadata": {
    "slideshow": {
     "slide_type": "slide"
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   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "posix\n",
      "Nazwa uzytkownika: tomasz\n"
     ]
    }
   ],
   "source": [
    "import os\n",
    "print(os.name)\n",
    "\n",
    "from os import getenv\n",
    "print('Nazwa uzytkownika: {}'.format(getenv(\"USER\")))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 21,
   "metadata": {
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     "slide_type": "slide"
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   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Counter({'o': 4, 'n': 4, 'a': 4, 'k': 3, 't': 3, 'y': 2, 'i': 2, 'c': 2, 'z': 2, 's': 1, 'p': 1, 'l': 1, 'ń': 1, 'w': 1, 'e': 1})\n"
     ]
    },
    {
     "data": {
      "text/plain": [
       "array([[1., 3., 4., 5.]], dtype=float32)"
      ]
     },
     "execution_count": 21,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "from collections import *\n",
    "print(Counter(\"konstantynopolitańczykowianeczka\"))\n",
    "\n",
    "import numpy as np\n",
    "np.array([[1, 3, 4, 5]], dtype='float32')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
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