{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Lists  \n",
    "* List items are ordered, changeable, and allow duplicate values.\n",
    "* List items are indexed, the first item has index [0], the second item has index [1] etc  \n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**Creating a List**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['Apple', 'Banana', 'Orange', 'Data', 'Test']\n"
     ]
    }
   ],
   "source": [
    "myList = ['Apple', 'Banana', 'Orange', 'Data', 'Test']\n",
    "\n",
    "print(myList)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Apple\n",
      "Banana\n",
      "Orange\n",
      "Data\n",
      "Test\n"
     ]
    }
   ],
   "source": [
    "# printing each element\n",
    "for i in myList:\n",
    "    print(i)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**Another way to Create a list**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[]\n"
     ]
    }
   ],
   "source": [
    "myList1 = list()  # Empty List\n",
    "print(myList1)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**Adding Elements**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['One', 'Two']\n"
     ]
    }
   ],
   "source": [
    "myList1.append('One')\n",
    "myList1.append('Two')\n",
    "print(myList1)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[2.2, 'One', 3, 'Integer']\n"
     ]
    }
   ],
   "source": [
    "# Creating an List by direct assignment\n",
    "myList2 = list([2.2, 'One', 3, 'Integer'])\n",
    "print(myList2)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**Selecting an element by index value**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2.2\n"
     ]
    }
   ],
   "source": [
    "print(myList2[0])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "3\n"
     ]
    }
   ],
   "source": [
    "print(myList2[2])"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**Out of Index Error**  \n",
    "List index starts from 0 till n-1 where n is the no of element in the list"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "ename": "IndexError",
     "evalue": "list index out of range",
     "output_type": "error",
     "traceback": [
      "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[1;31mIndexError\u001b[0m                                Traceback (most recent call last)",
      "\u001b[1;32m<ipython-input-10-82396407b7b4>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m\u001b[0m\n\u001b[1;32m----> 1\u001b[1;33m \u001b[0mprint\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mmyList2\u001b[0m\u001b[1;33m[\u001b[0m\u001b[1;36m4\u001b[0m\u001b[1;33m]\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m",
      "\u001b[1;31mIndexError\u001b[0m: list index out of range"
     ]
    }
   ],
   "source": [
    "print(myList2[4])"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**Slicing**    \n",
    "Way to select or slice element from list"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['Orange', 'Data', 'Test']\n"
     ]
    }
   ],
   "source": [
    "# Select all element from index 2 to end\n",
    "print(myList[2:])   "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Test\n"
     ]
    }
   ],
   "source": [
    "# Get last element \n",
    "# Index nos will start from -1 to -n in backward list where n is the no of elements in list\n",
    "print(myList[-1])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['Orange', 'Data']\n"
     ]
    }
   ],
   "source": [
    "# Get element from index 2 except the last one\n",
    "print(myList[2:-1])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['Test', 'Data', 'Orange', 'Banana', 'Apple']\n"
     ]
    }
   ],
   "source": [
    "# Reversing the whole list\n",
    "print(myList[::-1])"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**Element Exists??**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[True]"
      ]
     },
     "execution_count": 16,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "['Test' in myList]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[False]"
      ]
     },
     "execution_count": 17,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "['Mango' in myList]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "True"
      ]
     },
     "execution_count": 18,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "'Banana' in myList"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**No of elements in list or lenght**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 19,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "5"
      ]
     },
     "execution_count": 19,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "len(myList)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**Manupulating a List**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 20,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['Apple', 'Banana', 'Orange', 'Data', 'Test', 0]\n"
     ]
    }
   ],
   "source": [
    "# Appending an element 0\n",
    "myList.append(0)\n",
    "print(myList)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 21,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['Apple', '2', 'Banana', 'Orange', 'Data', 'Test', 0]\n"
     ]
    }
   ],
   "source": [
    "# Inserting an element at index 1 (2nd element)\n",
    "myList.insert(1, '2')\n",
    "print(myList)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0\n",
      "['Apple', '2', 'Banana', 'Orange', 'Data', 'Test']\n"
     ]
    }
   ],
   "source": [
    "# Removing the last element\n",
    "last = myList.pop()\n",
    "print(last)\n",
    "print(myList)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 23,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "None\n",
      "['Apple', 'Banana', 'Orange', 'Data', 'Test']\n"
     ]
    }
   ],
   "source": [
    "# Removing the element 2\n",
    "item = myList.remove('2')\n",
    "print(item)\n",
    "print(myList)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 24,
   "metadata": {},
   "outputs": [
    {
     "ename": "ValueError",
     "evalue": "list.remove(x): x not in list",
     "output_type": "error",
     "traceback": [
      "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[1;31mValueError\u001b[0m                                Traceback (most recent call last)",
      "\u001b[1;32m<ipython-input-24-44aa9d2032c4>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m\u001b[0m\n\u001b[0;32m      1\u001b[0m \u001b[1;31m# Removing element which does not exists\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m----> 2\u001b[1;33m \u001b[0mitem\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mmyList\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mremove\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;34m'Pop'\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m      3\u001b[0m \u001b[0mprint\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mitem\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m      4\u001b[0m \u001b[0mprint\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mmyList\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;31mValueError\u001b[0m: list.remove(x): x not in list"
     ]
    }
   ],
   "source": [
    "# Removing element which does not exists\n",
    "item = myList.remove('Pop')\n",
    "print(item)\n",
    "print(myList)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 25,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[]\n"
     ]
    }
   ],
   "source": [
    "# Clearing the whole list \n",
    "myList2.clear()   # can be done as re-initialization the variable -->  myLList2 =[]\n",
    "print(myList2)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 26,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['Test', 'Data', 'Orange', 'Banana', 'Apple']\n"
     ]
    }
   ],
   "source": [
    "myList.reverse()   # inplace reverse\n",
    "print(myList)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 27,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['Apple', 'Banana', 'Data', 'Orange', 'Test']\n"
     ]
    }
   ],
   "source": [
    "myList.sort()    # inplace sort\n",
    "print(myList)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 32,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "list2 before -->  ['Apple', 'Banana', 'Data', 'Orange', 'Test']\n",
      "list2 after  -->  ['Test', 'Orange', 'Data', 'Banana', 'Apple']\n",
      "myList -->  ['Apple', 'Banana', 'Data', 'Orange', 'Test']\n"
     ]
    }
   ],
   "source": [
    "list2 = myList.copy()      # creating a copy\n",
    "print(\"list2 before --> \",list2)\n",
    "list2.reverse()\n",
    "print(\"list2 after  --> \",list2)\n",
    "print(\"myList --> \",myList)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 33,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "list2 -->  ['Test', 'Orange', 'Data', 'Banana', 'Apple']\n",
      "list3 -->  ['Apple', 'Banana', 'Data', 'Orange', 'Test']\n"
     ]
    }
   ],
   "source": [
    "list3 = sorted(list2)      # Create another copy\n",
    "print(\"list2 --> \",list2)\n",
    "print(\"list3 --> \",list3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 31,
   "metadata": {},
   "outputs": [],
   "source": [
    "# clearing all the list\n",
    "myList=[]\n",
    "myList2=[]\n",
    "list2=[]\n",
    "list3=[]"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**Concat**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 34,
   "metadata": {},
   "outputs": [],
   "source": [
    "list2 = ['this', 'is', 'another', 'data']\n",
    "list3 = ['which', 'we', 'are', 'going', 'to', 'manipulate']"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 36,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "list2 -->  ['this', 'is', 'another', 'data']\n",
      "list3 -->  ['which', 'we', 'are', 'going', 'to', 'manipulate']\n",
      "['this', 'is', 'another', 'data', 'which', 'we', 'are', 'going', 'to', 'manipulate']\n"
     ]
    }
   ],
   "source": [
    "print(\"list2 --> \", list2)\n",
    "print(\"list3 --> \", list3)\n",
    "\n",
    "myList = list2 + list3\n",
    "print(myList)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 37,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['this', 'is', 'another', 'data', 'which', 'we', 'are', 'going', 'to', 'manipulate']\n"
     ]
    }
   ],
   "source": [
    "# Print all elements\n",
    "print(myList[:])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 38,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['which', 'we', 'are']\n"
     ]
    }
   ],
   "source": [
    "# Get element from index 4 till 6\n",
    "print(myList[4:7])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 39,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['this', 'is']\n"
     ]
    }
   ],
   "source": [
    "# Get element from 0 to 1\n",
    "print(myList[:2])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 40,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['this', 'another', 'which', 'are']\n"
     ]
    }
   ],
   "source": [
    "# Get element from 0 to 6 with 2 hops/steps\n",
    "print(myList[:7:2])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 41,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['this', 'which', 'to']\n"
     ]
    }
   ],
   "source": [
    "# Get all element with 4 hops\n",
    "print(myList[::4])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 42,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['manipulate', 'we', 'is']\n"
     ]
    }
   ],
   "source": [
    "# Get all element with 4 hops but backward\n",
    "print(myList[::-4])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 43,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['manipulate', 'to', 'going', 'are', 'we', 'which', 'data', 'another', 'is', 'this']\n"
     ]
    }
   ],
   "source": [
    "# Reverse the whole list\n",
    "print(myList[::-1])"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**Copy List**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 44,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "list2 -->  ['this', 'is', 'another', 'data']\n",
      "list4 -->  ['this', 'is', 'another', 'data']\n",
      "list5 -->  ['this', 'is', 'another', 'data']\n",
      "list6 -->  ['this', 'is', 'another', 'data']\n"
     ]
    }
   ],
   "source": [
    "list4 = list2           # Copy be reference\n",
    "list5 = list2.copy()    \n",
    "list6 = list2[:]\n",
    "\n",
    "print(\"list2 --> \", list2)\n",
    "print(\"list4 --> \", list4)\n",
    "print(\"list5 --> \", list5)\n",
    "print(\"list6 --> \", list6)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 45,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "list2 -->  ['this', 'are', 'another', 'data']\n",
      "list4 -->  ['this', 'are', 'another', 'data']\n",
      "list5 -->  ['this', 'is', 'another', 'data']\n",
      "list6 -->  ['this', 'is', 'another', 'data']\n"
     ]
    }
   ],
   "source": [
    "list2[1] = 'are'   # altering list2 2nd element\n",
    "\n",
    "print(\"list2 --> \", list2)\n",
    "print(\"list4 --> \", list4)\n",
    "print(\"list5 --> \", list5)\n",
    "print(\"list6 --> \", list6)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 47,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "list2 -->  ['this', 'are', 'another', 'data', 'extra', 'extra']\n",
      "list4 -->  ['this', 'are', 'another', 'data', 'extra', 'extra']\n",
      "list5 -->  ['this', 'is', 'another', 'data']\n",
      "list6 -->  ['this', 'is', 'another', 'data']\n"
     ]
    }
   ],
   "source": [
    "list2.append('extra')\n",
    "\n",
    "print(\"list2 --> \", list2)\n",
    "print(\"list4 --> \", list4)\n",
    "print(\"list5 --> \", list5)\n",
    "print(\"list6 --> \", list6)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**List Comprehension**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 54,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]\n"
     ]
    }
   ],
   "source": [
    "# List Comprehension\n",
    "\n",
    "arr = list(range(1,20))\n",
    "print(arr)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 55,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, 196, 225, 256, 289, 324, 361]\n"
     ]
    }
   ],
   "source": [
    "# Creating another list from arr\n",
    "arr2 = [ i*i for i in arr]\n",
    "print(arr2)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 57,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[2, 4, 6, 8, 10, 12, 14, 16, 18]"
      ]
     },
     "execution_count": 57,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# Fetch only even value via comprehention\n",
    "[i for i in arr if i%2==0 ]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 64,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[0, 2, 0, 4, 0, 6, 0, 8, 0, 10, 0, 12, 0, 14, 0, 16, 0, 18, 0]"
      ]
     },
     "execution_count": 64,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "[i if i%2==0 else 0 for i in arr ]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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