Python tutorial for programmers

Python part 1.ipynb

Python part 2.ipynb

Python part 3.ipynb

Python part 4.ipynb

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  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Python cz\u0119\u015b\u0107 4"
     ]
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Dekoratory"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "W internecie jest a\u017c za du\u017co miejsc gdzie mo\u017cna przeczyta\u0107 jak to dzia\u0142a."
     ]
    },
    {
     "cell_type": "heading",
     "level": 4,
     "metadata": {},
     "source": [
      "Proste dekoratory"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "def wykonajdwarazy(func):\n",
      "    def wrapper(*args, **kwargs):\n",
      "        func(*args, **kwargs)\n",
      "        func(*args, **kwargs)\n",
      "    \n",
      "    return wrapper\n",
      "\n",
      "@wykonajdwarazy\n",
      "def f(n):\n",
      "    print(n)\n",
      "\n",
      "f(10)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "10\n",
        "10\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "def g(n):\n",
      "    print(\"g\", n)\n",
      "\n",
      "g = wykonajdwarazy(g)\n",
      "\n",
      "g(1)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "g 1\n",
        "g 1\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "@wykonajdwarazy\n",
      "@wykonajdwarazy\n",
      "def f(n):\n",
      "    print(n)\n",
      "    \n",
      "f(10)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "10\n",
        "10\n",
        "10\n",
        "10\n"
       ]
      }
     ],
     "prompt_number": 3
    },
    {
     "cell_type": "heading",
     "level": 4,
     "metadata": {},
     "source": [
      "Dekoratory przyjmuj\u0105ce argumenty"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "def my_filter(*args):\n",
      "    def decorator(func):\n",
      "        def wrapper(arg):\n",
      "            if arg in args:\n",
      "                return func(arg)\n",
      "            return None\n",
      "        return wrapper\n",
      "    return decorator\n",
      "\n",
      "@my_filter(1,2,3)\n",
      "def f(n):\n",
      "    print(n)\n",
      "\n",
      "f(10)\n",
      "f(1)\n",
      "f(5)\n",
      "f(2)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "1\n",
        "2\n"
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "heading",
     "level": 4,
     "metadata": {},
     "source": [
      "Dekorowanie klas"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "def c(cls):\n",
      "    class klass(cls):\n",
      "        def __init__(self, *args, **kwargs):\n",
      "            super().__init__(*args, **kwargs)\n",
      "            print(\"init\")\n",
      "            \n",
      "    return klass\n",
      "\n",
      "@c\n",
      "class B:\n",
      "    pass\n",
      "\n",
      "a = B()\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "init\n"
       ]
      }
     ],
     "prompt_number": 5
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "class D(B):\n",
      "    pass\n",
      "\n",
      "d = D()"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "init\n"
       ]
      }
     ],
     "prompt_number": 6
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "S\u0142\u00f3wka kluczowe `global` i `nonlocal`"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "a = 5\n",
      "\n",
      "def f():\n",
      "    global a\n",
      "    a += 1\n",
      "    \n",
      "f()\n",
      "f()\n",
      "f()\n",
      "print(a)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "8\n"
       ]
      }
     ],
     "prompt_number": 7
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "def f():\n",
      "    counter = 0\n",
      "    \n",
      "    def n():\n",
      "        nonlocal counter\n",
      "        counter += 1\n",
      "        return counter\n",
      "    \n",
      "    return n\n",
      "\n",
      "c = f()\n",
      "\n",
      "print(c())\n",
      "print(c())\n",
      "print(f())\n",
      "\n",
      "d = f()\n",
      "print(d())\n",
      "print(d())\n",
      "\n",
      "print(f()())"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "1\n",
        "2\n",
        "<function f.<locals>.n at 0x2b0a4f971f28>\n",
        "1\n",
        "2\n",
        "1\n"
       ]
      }
     ],
     "prompt_number": 8
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Adnotacje"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "https://www.python.org/dev/peps/pep-3107/"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "def f(a : 3, b : \"asdasd\", d : 1 = 10) -> \"asdasd\":\n",
      "    \"asdasdasdasd\"\n",
      "    pass\n",
      "\n",
      "print(f.__annotations__)\n",
      "print(f.__doc__)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "{'b': 'asdasd', 'return': 'asdasd', 'd': 1, 'a': 3}\n",
        "asdasdasdasd\n"
       ]
      }
     ],
     "prompt_number": 9
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Deskryptory"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Polecam artyku\u0142: http://nbviewer.ipython.org/gist/ChrisBeaumont/5758381/descriptor_writeup.ipynb"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "class A:\n",
      "    def __init__(self):\n",
      "        self.a = 0\n",
      "        \n",
      "    @property\n",
      "    def a_plus_one(self):\n",
      "        return self.a + 1\n",
      "    \n",
      "    @a_plus_one.setter\n",
      "    def a_plus_one(self, value):\n",
      "        self.a = value - 1\n",
      "        \n",
      "a = A()\n",
      "a.a = 10\n",
      "print(a.a_plus_one)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "11\n"
       ]
      }
     ],
     "prompt_number": 10
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "class D:\n",
      "    def __init__(self, name):\n",
      "        self.name = name\n",
      "        \n",
      "    def __get__(self, obj, cls):\n",
      "        return self.name\n",
      "        \n",
      "    def __set__(self, obj, value):\n",
      "        self.name = value\n",
      "\n",
      "\n",
      "class A:\n",
      "    d = D(\"marek\")\n",
      "\n",
      "a = A()\n",
      "print(a.d)\n",
      "a.d = 10\n",
      "print(a.d)\n",
      "\n",
      "b = A()\n",
      "print(a.d)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "marek\n",
        "10\n",
        "10\n"
       ]
      }
     ],
     "prompt_number": 11
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 11
    }
   ],
   "metadata": {}
  }
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