Part 4, Sections 02 and 03

Author: Fred Baptiste

Part 4/Section 02 - Classes/01 - Objects and Classes.ipynb

@@ -0,0 +1,179 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Callable Class Attributes"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Class attributes can be any object type, including callables such as functions:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class Program:\n",
+    "    language = 'Python'\n",
+    "    \n",
+    "    def say_hello():\n",
+    "        print(f'Hello from {Program.language}!')"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "mappingproxy({'__module__': '__main__',\n",
+       "              'language': 'Python',\n",
+       "              'say_hello': <function __main__.Program.say_hello()>,\n",
+       "              '__dict__': <attribute '__dict__' of 'Program' objects>,\n",
+       "              '__weakref__': <attribute '__weakref__' of 'Program' objects>,\n",
+       "              '__doc__': None})"
+      ]
+     },
+     "execution_count": 2,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "Program.__dict__"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "As we can see, the `say_hello` symbol is in the class dictionary.\n",
+    "\n",
+    "We can also retrieve it using either `getattr` or dotted notation:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "(<function __main__.Program.say_hello()>,\n",
+       " <function __main__.Program.say_hello()>)"
+      ]
+     },
+     "execution_count": 3,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "Program.say_hello, getattr(Program, 'say_hello')"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "And of course we can call it, since it is a callable:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Hello from Python!\n"
+     ]
+    }
+   ],
+   "source": [
+    "Program.say_hello()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Hello from Python!\n"
+     ]
+    }
+   ],
+   "source": [
+    "getattr(Program, 'say_hello')()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "We can even access it via the namespace dictionary as well:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Hello from Python!\n"
+     ]
+    }
+   ],
+   "source": [
+    "Program.__dict__['say_hello']()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "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": "3.6.7"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}