{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Python для сбора и анализа данных\n",
    "\n",
    "*Алла Тамбовцева, НИУ ВШЭ*"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Генераторы списков (списковые включения)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "nums = [1, 8, 23, 45, 67]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[1, 64, 529, 2025, 4489]\n"
     ]
    }
   ],
   "source": [
    "nums_sq = [] \n",
    "for n in nums:\n",
    "    nums_sq.append(n ** 2)\n",
    "print(nums_sq) "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[1, 64, 529, 2025, 4489]\n"
     ]
    }
   ],
   "source": [
    "nums_sq = [n ** 2 for n in nums] \n",
    "print(nums_sq) "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1.52 ms ± 15.9 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)\n"
     ]
    }
   ],
   "source": [
    "%%timeit\n",
    "R = []\n",
    "for i in range(0, 5001):\n",
    "    R.append(i ** 3) "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1.35 ms ± 10.5 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)\n"
     ]
    }
   ],
   "source": [
    "%%timeit\n",
    "R = [i ** 3 for i in range(0, 5001)] "
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Функция `enumerate()`"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [],
   "source": [
    "drinks = ['tea', 'coffee', 'juice', 'milk'] "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0 tea\n",
      "1 coffee\n",
      "2 juice\n",
      "3 milk\n"
     ]
    }
   ],
   "source": [
    "for d in drinks:\n",
    "    print(drinks.index(d), d)  # метод index()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0 tea\n",
      "1 coffee\n",
      "2 juice\n",
      "3 milk\n"
     ]
    }
   ],
   "source": [
    "for i in range(0, len(drinks)):\n",
    "    print(i, drinks[i]) "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "<enumerate at 0x10dc97a50>"
      ]
     },
     "execution_count": 9,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "enumerate(drinks)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[(0, 'tea'), (1, 'coffee'), (2, 'juice'), (3, 'milk')]"
      ]
     },
     "execution_count": 10,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "list(enumerate(drinks))  # list of tuple"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0 tea\n",
      "1 coffee\n",
      "2 juice\n",
      "3 milk\n"
     ]
    }
   ],
   "source": [
    "for i, d in enumerate(drinks):\n",
    "    print(i, d) "
   ]
  }
 ],
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