Lambda Expression Map and Filter.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "id": "b74fc488",
   "metadata": {},
   "source": [
    "# Map"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "id": "630e4540",
   "metadata": {},
   "outputs": [],
   "source": [
    "def square(num):\n",
    "    return num**2"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "b505c94f",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1\n",
      "4\n",
      "9\n",
      "16\n",
      "25\n"
     ]
    }
   ],
   "source": [
    "my_nums = [1, 2, 3, 4, 5]\n",
    "\n",
    "for items in map(square, my_nums):\n",
    "    print(items)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "id": "844ae29f",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[1, 4, 9, 16, 25]"
      ]
     },
     "execution_count": 5,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "list(map(square, my_nums))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "id": "c90053f9",
   "metadata": {},
   "outputs": [],
   "source": [
    "# For string:\n",
    "\n",
    "def hobit(mystring):\n",
    "    if len(mystring) % 2 == 0:\n",
    "        return \"Even\"\n",
    "    else:\n",
    "        return mystring[0]\n",
    "        "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "id": "a1b8f939",
   "metadata": {},
   "outputs": [],
   "source": [
    "names = [\"Thorin\", \"Bilbo\", \"Gandalf\"]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "id": "02a7b137",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['Even', 'B', 'G']"
      ]
     },
     "execution_count": 12,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "list(map(hobit, names))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "f040ccdc",
   "metadata": {},
   "source": [
    "# Filter"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "id": "7622717b",
   "metadata": {},
   "outputs": [],
   "source": [
    "def check_even(num):\n",
    "    return num % 2 == 0"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "id": "dfa8c159",
   "metadata": {},
   "outputs": [],
   "source": [
    "my_nums = [1, 2, 3, 4, 5]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "id": "ccad4a0c",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2\n",
      "4\n"
     ]
    }
   ],
   "source": [
    "for _ in filter(check_even, my_nums):\n",
    "    print(_)\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "id": "9bb8be43",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[2, 4]"
      ]
     },
     "execution_count": 16,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "list(filter(check_even, my_nums))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "9886a483",
   "metadata": {},
   "source": [
    "# Lambda"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 24,
   "id": "e26319af",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[1, 4, 9, 16, 25]"
      ]
     },
     "execution_count": 24,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "list(map(lambda num : num**2, my_nums))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 25,
   "id": "8ab6819b",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[2, 4]"
      ]
     },
     "execution_count": 25,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "list(filter(lambda num : num % 2 == 0, my_nums))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 27,
   "id": "efbe2297",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['Thorin', 'Bilbo', 'Gandalf']"
      ]
     },
     "execution_count": 27,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "names"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 30,
   "id": "dca7b90d",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['T', 'B', 'G']"
      ]
     },
     "execution_count": 30,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "list(map(lambda _ : _[0], names))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 31,
   "id": "1e29f592",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['nirohT', 'obliB', 'fladnaG']"
      ]
     },
     "execution_count": 31,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "list(map(lambda _ : _[::-1], names))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "a73d9c84",
   "metadata": {},
   "outputs": [],
   "source": []
  }
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