{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "1. Read a file from a csv file stored in your computer.\n",
    "\n",
    "`import csv\n",
    "reader = csv.reader(open('filename.csv', 'r'))`\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "import csv\n",
    "reader = csv.reader(open('filename.csv', 'r'))\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "2. Create a list of rows. \n",
    "\n",
    "When iterating the object reader, it converts each row into a list\n",
    "\n",
    "`???\n",
    "for rowList in reader:\n",
    "    ????\n",
    "print (listA)`\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[['joao', '22'], ['maria', '21'], ['manuela', '23'], ['antonio', '22']]\n"
     ]
    }
   ],
   "source": [
    "listA = []\n",
    "for rowList in reader:\n",
    "    listA.append(rowList)\n",
    "print(listA)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "3. The result is similar to `[['joao', '22'], ['maria', '21'], ['manuela', '23'], ['antonio', '22']]`. So you have to convert the age from strings to integers or floats. If you use the function len it will gives you the number of rows."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[['joao', 22], ['maria', 21], ['manuela', 23], ['antonio', 22]]"
      ]
     },
     "execution_count": 6,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "for pair in listA:\n",
    "    pair[1] = int(pair[1])\n",
    "listA"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "4. What is the average age of the students of the list?"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "22.0\n"
     ]
    }
   ],
   "source": [
    "Sum = 0\n",
    "for pair in listA:\n",
    "    Sum += pair[1]\n",
    "avg = Sum/len(listA)\n",
    "print(avg)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "22.0"
      ]
     },
     "execution_count": 9,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "list1 = []\n",
    "list2 = []\n",
    "for i in listA:\n",
    "    list1.append(i[0])\n",
    "    list2.append(i[1])\n",
    "list2 \n",
    "a= sum(list2)/len(list2)\n",
    "a"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "5. What is the age of the older student?"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "23"
      ]
     },
     "execution_count": 11,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "ages = [pair[1] for pair in listA]\n",
    "max(ages)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "6. Who is the older student? (suppose that ther is only on)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "manuela\n"
     ]
    }
   ],
   "source": [
    "for a in listA:\n",
    "    if a[1]==max(ages):\n",
    "        print(a[0])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'manuela'"
      ]
     },
     "execution_count": 13,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "listA[ages.index(max(ages))][0]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
 ],
 "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": "3.7.0"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 4
}