Python2017/labs04/Klasy.ipynb
2017-12-16 09:04:22 +01:00

663 lines
15 KiB
Plaintext
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

{
"cells": [
{
"cell_type": "markdown",
"metadata": {
"collapsed": true,
"slideshow": {
"slide_type": "slide"
}
},
"source": [
"# Wprowadzenie do Pythona: Klasy\n",
"\n",
"## Tomasz Dwojak\n",
"\n",
"### 3 grudnia 2017"
]
},
{
"cell_type": "markdown",
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"source": [
"# Plan na dziś:\n",
" * klasy,\n",
" * wyjątki."
]
},
{
"cell_type": "markdown",
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"source": [
"## Python jest językiem obiektowym \n",
" * Wszystko jest obiektem: liczby, napisy, None, funkcje, moduły (biblioteki)..."
]
},
{
"cell_type": "code",
"execution_count": 11,
"metadata": {
"slideshow": {
"slide_type": "fragment"
}
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"0\n",
"Python da się lubić !\n"
]
}
],
"source": [
"print((2017).imag)\n",
"print(' '.join(['Python', 'da', 'się', 'lubić', '!']))"
]
},
{
"cell_type": "markdown",
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"source": [
"## Konstrukcja"
]
},
{
"cell_type": "code",
"execution_count": 18,
"metadata": {
"slideshow": {
"slide_type": "fragment"
}
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"<class '__main__.NajprostszaKlasa'>\n"
]
}
],
"source": [
"class NajprostszaKlasa:\n",
" pass\n",
"\n",
"nasza_klasa = NajprostszaKlasa() # Uwaga na nawiasy na końcu!\n",
"print(type(nasza_klasa))"
]
},
{
"cell_type": "markdown",
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"source": [
"## (Pseudo) Konstruktor \n",
"\n"
]
},
{
"cell_type": "code",
"execution_count": 30,
"metadata": {
"slideshow": {
"slide_type": "fragment"
}
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"2\n"
]
}
],
"source": [
"class Punkt:\n",
" def __init__(self, x, y):\n",
" self.x = x\n",
" self.y = y\n",
"\n",
"punkt = Punkt(2, 3)\n",
"print(punkt.x)"
]
},
{
"cell_type": "code",
"execution_count": 25,
"metadata": {
"collapsed": true,
"slideshow": {
"slide_type": "slide"
}
},
"outputs": [],
"source": [
"class Figura:\n",
" def __init__(self, vertexes):\n",
" self.vertexes = vertexes\n",
" \n",
" def liczba_wierzcholkow(self):\n",
" return len(self.vertexes)\n",
" \n",
" def dodaj_wierzcholek(self, x):\n",
" self.vertexes.append(x)"
]
},
{
"cell_type": "code",
"execution_count": 26,
"metadata": {
"collapsed": true,
"slideshow": {
"slide_type": "slide"
}
},
"outputs": [],
"source": [
"class Prostokat(Figura):\n",
" def __init__(self, vertexes):\n",
" super().__init__(vertexes)\n",
" \n",
" def czy_jestem_kwadratem(self):\n",
" pass\n",
" "
]
},
{
"cell_type": "code",
"execution_count": 28,
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"outputs": [
{
"data": {
"text/plain": [
"3"
]
},
"execution_count": 28,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"class Figura:\n",
" def __init__(self, vertexes):\n",
" self.vertexes = vertexes\n",
" \n",
" def liczba_wierzcholkow(self):\n",
" return len(self.vertexes)\n",
" \n",
" def __len__(self):\n",
" return self.liczba_wierzcholkow()\n",
" \n",
"len(Figura([Punkt(2,3), Punkt(3,4), Punkt(0, 0)]))"
]
},
{
"cell_type": "markdown",
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"source": [
"## Dobre praktyki: komentarze"
]
},
{
"cell_type": "code",
"execution_count": 4,
"metadata": {
"slideshow": {
"slide_type": "fragment"
}
},
"outputs": [],
"source": [
"class Punkt(object):\n",
" \"\"\"Klasa reprezentująca punkt w 2D.\"\"\"\n",
" def __init__(self, x, y):\n",
" \"\"\"opis argumentów x i y.\"\"\"\n",
" self.x = x\n",
" self.y = y"
]
},
{
"cell_type": "code",
"execution_count": 5,
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Help on class Punkt in module __main__:\n",
"\n",
"class Punkt(builtins.object)\n",
" | Klasa reprezentująca punkt w 2D.\n",
" | \n",
" | Methods defined here:\n",
" | \n",
" | __init__(self, x, y)\n",
" | opis argumentów x i y.\n",
" | \n",
" | ----------------------------------------------------------------------\n",
" | Data descriptors defined here:\n",
" | \n",
" | __dict__\n",
" | dictionary for instance variables (if defined)\n",
" | \n",
" | __weakref__\n",
" | list of weak references to the object (if defined)\n",
"\n"
]
}
],
"source": [
"help(Punkt)"
]
},
{
"cell_type": "markdown",
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"source": [
"## Enkapsulacja: publiczne czy prywatne?\n",
" * Prywatne zaczynają się od dwóch podkreśleń: ``__``, np. ``def __policz(self)``\n",
" * chronione tylko w konwencji, zaczynają się od '\\_', np. ``def _parse(self)``\n",
" * publiczne jest wszystko co nie zaczyna się od '\\_'."
]
},
{
"cell_type": "code",
"execution_count": 6,
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"outputs": [
{
"ename": "AttributeError",
"evalue": "'Parser' object has no attribute '__parse'",
"traceback": [
"\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
"\u001b[0;31mAttributeError\u001b[0m Traceback (most recent call last)",
"\u001b[0;32m<ipython-input-6-80ee186598d3>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[1;32m 4\u001b[0m \u001b[0mparser\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mParser\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m 5\u001b[0m \u001b[0mparser\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0m_get\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m----> 6\u001b[0;31m \u001b[0mparser\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0m__parse\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
"\u001b[0;31mAttributeError\u001b[0m: 'Parser' object has no attribute '__parse'"
],
"output_type": "error"
}
],
"source": [
"class Parser(object):\n",
" def __parse(self): pass\n",
" def _get(self): pass\n",
"parser = Parser()\n",
"parser._get()\n",
"parser.__parse()"
]
},
{
"cell_type": "markdown",
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"source": [
"## Iteratory"
]
},
{
"cell_type": "code",
"execution_count": 7,
"metadata": {
"slideshow": {
"slide_type": "fragment"
}
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"<__main__.Punkt object at 0x7f728015b358>\n",
"<__main__.Punkt object at 0x7f728015b4a8>\n",
"<__main__.Punkt object at 0x7f728015b438>\n"
]
}
],
"source": [
"class Figura:\n",
" def __init__(self, vertexes):\n",
" self.vertexes = vertexes \n",
" \n",
" def __iter__(self):\n",
" self.index = -1\n",
" return self\n",
" \n",
" def __next__(self):\n",
" self.index += 1\n",
" if self.index == len(self.vertexes):\n",
" raise StopIteration\n",
" return self.vertexes[self.index]\n",
" \n",
"for v in Figura([Punkt(2,3), Punkt(3,4), Punkt(0, 0)]):\n",
" print(v)"
]
},
{
"cell_type": "markdown",
"metadata": {
"collapsed": true,
"slideshow": {
"slide_type": "slide"
}
},
"source": [
"## Atrybuty i metody statyczne"
]
},
{
"cell_type": "code",
"execution_count": 16,
"metadata": {
"slideshow": {
"slide_type": "fragment"
}
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"0\n",
"0\n"
]
}
],
"source": [
"class Klasa:\n",
" atrybut = 0\n",
"\n",
"klasa = Klasa()\n",
"print(Klasa.atrybut)\n",
"print(klasa.atrybut)"
]
},
{
"cell_type": "code",
"execution_count": 19,
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Jestem statyczna!\n"
]
}
],
"source": [
"class Klasa:\n",
" def __init__(self):\n",
" self.t = 0\n",
" def metoda():\n",
" print(\"Jestem statyczna!\")\n",
"\n",
"Klasa.metoda()"
]
},
{
"cell_type": "markdown",
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"source": [
"## Wyjątki"
]
},
{
"cell_type": "code",
"execution_count": 20,
"metadata": {
"slideshow": {
"slide_type": "fragment"
}
},
"outputs": [
{
"ename": "FileNotFoundError",
"evalue": "[Errno 2] No such file or directory: 'nieistniejący_plik.txt'",
"traceback": [
"\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
"\u001b[0;31mFileNotFoundError\u001b[0m Traceback (most recent call last)",
"\u001b[0;32m<ipython-input-20-41928d542bef>\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\"nieistniejący_plik.txt\"\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[0m\n\u001b[0m\u001b[1;32m 2\u001b[0m \u001b[0mprint\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mplik\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mread\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[0;31mFileNotFoundError\u001b[0m: [Errno 2] No such file or directory: 'nieistniejący_plik.txt'"
],
"output_type": "error"
}
],
"source": [
"with open(\"nieistniejący_plik.txt\") as plik:\n",
" content = plik.read()"
]
},
{
"cell_type": "code",
"execution_count": 23,
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"outputs": [],
"source": [
"try:\n",
" with open(\"nieistniejący_plik.txt\") as plik:\n",
" content = plik.read()\n",
"except FileNotFoundError:\n",
" contenct = \"\""
]
},
{
"cell_type": "code",
"execution_count": 27,
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Warning [Errno 2] No such file or directory: 'nieistniejący_plik.txt'\n"
]
}
],
"source": [
"try:\n",
" with open(\"nieistniejący_plik.txt\") as plik:\n",
" content = plik.read()\n",
"except FileNotFoundError as e:\n",
" print(\"Warning {}\".format(e))\n",
" contenct = \"\""
]
},
{
"cell_type": "code",
"execution_count": 28,
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Warning [Errno 2] No such file or directory: 'nieistniejący_plik.txt'\n"
]
}
],
"source": [
"try:\n",
" with open(\"nieistniejący_plik.txt\") as plik:\n",
" content = plik.read()\n",
"except Exception as e:\n",
" print(\"Warning {}\".format(e))\n",
" contenct = \"\""
]
},
{
"cell_type": "code",
"execution_count": 29,
"metadata": {
"collapsed": true,
"slideshow": {
"slide_type": "slide"
}
},
"outputs": [],
"source": [
"try:\n",
" with open(\"nieistniejący_plik.txt\") as plik:\n",
" content = plik.read()\n",
"except:\n",
" contenct = \"\""
]
},
{
"cell_type": "code",
"execution_count": 30,
"metadata": {
"collapsed": true,
"slideshow": {
"slide_type": "slide"
}
},
"outputs": [],
"source": [
"class Figura:\n",
" def __init__(self, vertexes):\n",
" if len(vertexes) == 0:\n",
" raise Exception(\"Empty list of vertexes\")\n",
" self.vertexes = vertexes"
]
},
{
"cell_type": "code",
"execution_count": 35,
"metadata": {
"collapsed": true,
"slideshow": {
"slide_type": "slide"
}
},
"outputs": [],
"source": [
"class MyError(Exception):\n",
" def __init__(self, text):\n",
" self.text = text\n",
" def __str__(self):\n",
" return self.text"
]
},
{
"cell_type": "code",
"execution_count": 36,
"metadata": {
"slideshow": {
"slide_type": "fragment"
}
},
"outputs": [
{
"ename": "MyError",
"evalue": "Coś poszło nie tak!",
"traceback": [
"\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
"\u001b[0;31mMyError\u001b[0m Traceback (most recent call last)",
"\u001b[0;32m<ipython-input-36-4fb306b42ebc>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0;32mraise\u001b[0m \u001b[0mMyError\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m\"Coś poszło nie tak!\"\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
"\u001b[0;31mMyError\u001b[0m: Coś poszło nie tak!"
],
"output_type": "error"
}
],
"source": [
"raise MyError(\"Coś poszło nie tak!\")"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": []
}
],
"metadata": {
"celltoolbar": "Slideshow",
"kernelspec": {
"display_name": "Python 3",
"language": "python",
"name": "python3"
},
"language_info": {
"codemirror_mode": {
"name": "ipython",
"version": 3
},
"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython3",
"version": "3.6.3"
}
},
"nbformat": 4,
"nbformat_minor": 2
}