{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Function Caching"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "import time "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "def some_func(n):\n",
    "    \n",
    "    time.sleep(n)\n",
    "    return n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "5"
      ]
     },
     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "some_func(5)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "- caching / memoization"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "metadata": {},
   "outputs": [],
   "source": [
    "from functools import lru_cache\n",
    "import datetime\n",
    "@lru_cache(maxsize=3) ## latest 3 calls are saved\n",
    "def some_func(n):\n",
    "    \n",
    "    time.sleep(n)\n",
    "    return n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 23,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "time taken at first  0:00:10.001500\n"
     ]
    }
   ],
   "source": [
    "start = datetime.datetime.now()\n",
    "\n",
    "some_func(10)\n",
    "\n",
    "end = datetime.datetime.now()\n",
    "\n",
    "print(\"time taken at first \",end-start)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 24,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "time taken at second call  0:00:00.000255\n"
     ]
    }
   ],
   "source": [
    "start = datetime.datetime.now()\n",
    "\n",
    "some_func(10)\n",
    "\n",
    "end = datetime.datetime.now()\n",
    "\n",
    "print(\"time taken at second call \",end-start)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
 ],
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  "kernelspec": {
   "display_name": "Python 3",
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  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.8.3"
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 "nbformat": 4,
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