python_set.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Set"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### What' s set ?\n",
    "- set([iterable])\n",
    "- iterable (Optional) - a sequence (string, tuple, etc.) or collection (set, dictionary, etc.) or an iterator object to be converted into a set\n",
    "- unorder collection item  ---set---> unique(no duplicates) and must be immutable item"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Example : create set sequence"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "set()\n",
      "{'y', 'n', 'P', 't', 'o', 'h'}\n",
      "{'a', 'i', 'o', 'u', 'e'}\n",
      "{'a', 'i', 'o', 'u', 'e'}\n",
      "{0, 1, 2, 3, 4}\n"
     ]
    }
   ],
   "source": [
    "# empty set\n",
    "print(set())\n",
    "\n",
    "# from string\n",
    "print(set('Python'))\n",
    "\n",
    "# from tuple\n",
    "print(set(('a', 'e', 'i', 'o', 'u')))\n",
    "\n",
    "# from list\n",
    "print(set(['a', 'e', 'i', 'o', 'u']))\n",
    "\n",
    "# from range\n",
    "print(set(range(5)))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Example : Create set from dictionary and frozen set"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "{'a', 'o', 'i', 'u', 'e'}\n",
      "{'a', 'o', 'u', 'i', 'e'}\n",
      "{'a', 'o', 'i', 'u', 'e'}\n"
     ]
    }
   ],
   "source": [
    "# for set\n",
    "print(set({'a', 'e', 'i', 'o', 'u'}))\n",
    "\n",
    "# from dictionary\n",
    "print(set({'a':1, 'e': 2, 'i':3, 'o':4, 'u':5}))\n",
    "\n",
    "# from frozen set\n",
    "frozenSet = frozenset(('a', 'e', 'i', 'o', 'u'))\n",
    "print(set(frozenSet))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Example : From custom iterable object ?"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "{1, 2, 3, 4, 5}\n"
     ]
    }
   ],
   "source": [
    "class PrintNumber:\n",
    "    def __init__(self, max):\n",
    "        self.max = max\n",
    "\n",
    "    def __iter__(self):\n",
    "        self.num = 0\n",
    "        return self\n",
    "\n",
    "    def __next__(self):\n",
    "        if(self.num >= self.max):\n",
    "            raise StopIteration\n",
    "        self.num += 1\n",
    "        return self.num\n",
    "\n",
    "printNum = PrintNumber(5)\n",
    "\n",
    "# creating a set\n",
    "print(set(printNum))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Example : discard and remove"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "{1, 3, 4, 5, 6}\n",
      "{1, 3, 5, 6}\n",
      "{1, 3, 5}\n",
      "{1, 3, 5}\n"
     ]
    }
   ],
   "source": [
    "my_set = {1, 3, 4, 5, 6}\n",
    "print(my_set)\n",
    "# discard an element\n",
    "# Output: {1, 3, 5, 6}\n",
    "my_set.discard(4)\n",
    "print(my_set)\n",
    "\n",
    "# remove an element\n",
    "# Output: {1, 3, 5}\n",
    "my_set.remove(6)\n",
    "print(my_set)\n",
    "\n",
    "# discard an element\n",
    "# not present in my_set\n",
    "# Output: {1, 3, 5}\n",
    "my_set.discard(2)\n",
    "print(my_set)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Example : Pop and Clear"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "{'d', 'H', 'l', 'o', 'W', 'e', 'r'}\n",
      "d\n",
      "{'l', 'o', 'W', 'e', 'r'}\n",
      "set()\n"
     ]
    }
   ],
   "source": [
    "my_set = set(\"HelloWorld\")\n",
    "print(my_set)\n",
    "\n",
    "# pop an element\n",
    "# Output: random element\n",
    "print(my_set.pop())\n",
    "\n",
    "# pop another element\n",
    "# Output: random element\n",
    "my_set.pop()\n",
    "print(my_set)\n",
    "\n",
    "# clear my_set\n",
    "#Output: set()\n",
    "my_set.clear()\n",
    "print(my_set)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Example : Union"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "{1, 2, 3, 4, 5, 6, 7, 8}\n",
      "{1, 2, 3, 4, 5, 6, 7, 8}\n",
      "{1, 2, 3, 4, 5, 6, 7, 8}\n"
     ]
    }
   ],
   "source": [
    "# initialize A and B\n",
    "A = {1, 2, 3, 4, 5}\n",
    "B = {4, 5, 6, 7, 8}\n",
    "\n",
    "# use | operator\n",
    "# Output: {1, 2, 3, 4, 5, 6, 7, 8}\n",
    "print(A | B)\n",
    "print(A.union(B))\n",
    "print(B.union(A))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Example : Intersection"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "{4, 5}\n"
     ]
    },
    {
     "data": {
      "text/plain": [
       "{4, 5}"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# initialize A and B\n",
    "A = {1, 2, 3, 4, 5}\n",
    "B = {4, 5, 6, 7, 8}\n",
    "\n",
    "# use & operator\n",
    "# Output: {4, 5}\n",
    "print(A & B)\n",
    "print(A.intersection(B))\n",
    "print(B.intersection(A))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Example : Difference"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "{1, 2, 3}\n",
      "{1, 2, 3}\n",
      "{8, 6, 7}\n"
     ]
    }
   ],
   "source": [
    "# initialize A and B\n",
    "A = {1, 2, 3, 4, 5}\n",
    "B = {4, 5, 6, 7, 8}\n",
    "\n",
    "# use - operator on A\n",
    "# Output: {1, 2, 3}\n",
    "print(A - B)\n",
    "print(A.difference(B))\n",
    "print(B.difference(A))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Example : Symmetric Difference"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "{1, 2, 3, 6, 7, 8}\n",
      "{1, 2, 3, 6, 7, 8}\n",
      "{1, 2, 3, 6, 7, 8}\n"
     ]
    }
   ],
   "source": [
    "# initialize A and B\n",
    "A = {1, 2, 3, 4, 5}\n",
    "B = {4, 5, 6, 7, 8}\n",
    "\n",
    "# use ^ operator\n",
    "# Output: {1, 2, 3, 6, 7, 8}\n",
    "print(A ^ B)\n",
    "print(A.symmetric_difference(B))\n",
    "print(B.symmetric_difference(A))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Example : Test Member"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "True\n",
      "False\n"
     ]
    }
   ],
   "source": [
    "# initialize my_set\n",
    "my_set = set(\"apple\")\n",
    "\n",
    "# check if 'a' is present\n",
    "# Output: True\n",
    "print('a' in my_set)\n",
    "\n",
    "# check if 'p' is present\n",
    "# Output: False\n",
    "print('p' not in my_set)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Example : Iterating through a Set"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {
    "scrolled": true
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "a\n",
      "e\n",
      "p\n",
      "l\n"
     ]
    }
   ],
   "source": [
    "for letter in set(\"apple\"):\n",
    "    print(letter)"
   ]
  }
 ],
 "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": "3.6.5"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 2
}