{
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   "cell_type": "markdown",
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   "source": [
    "# Module 2\n",
    "\n",
    "## Video 6: Lists and List Operations\n",
    "**Python for the Energy Industry**\n",
    "\n",
    "## Lists\n",
    "\n",
    "We often want to keep track of many bits of data at once. One way of doing this in python is with a 'list'. Lists are defined by enclosing multiple comma-separated values inside square brackets."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "# list of strings\n",
    "vessels = ['ABIOLA', 'ACACIA']\n",
    "\n",
    "# list of floats\n",
    "prices = [1.23, 1.98, 1.45, 1.67]\n",
    "\n",
    "# lists of integers\n",
    "quantities1 = [18, 22, 21, 32]\n",
    "quantities2 = [12, 11, 16, 18]"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Looping Over Lists"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1.23\n",
      "1.98\n",
      "1.45\n",
      "1.67\n"
     ]
    }
   ],
   "source": [
    "# loop over prices\n",
    "for price in prices:\n",
    "    print(price)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### List Indexing\n",
    "\n",
    "We can access individual items in a list in the following way:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "The 1st price:  1.23\n",
      "The 2nd price:  1.98\n",
      "The 3rd price:  1.45\n"
     ]
    }
   ],
   "source": [
    "prices = [1.23, 1.98, 1.45, 1.67, 2.40, 1.89]\n",
    "\n",
    "print('The 1st price: ', prices[0] )\n",
    "print('The 2nd price: ', prices[1] )\n",
    "print('The 3rd price: ', prices[2] )"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "The number inside the square brackets is the 'index' of the item. Note that Python uses 'zero indexing', so the first item in a list has an index of 0.\n",
    "\n",
    "You can also access items 'from the end' using a negative index. So an index of -1 gives the last item, -2 gives the second last item, and so on."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "The last price:  1.89\n",
      "The 2nd last price:  2.4\n"
     ]
    }
   ],
   "source": [
    "print('The last price: ', prices[-1] )\n",
    "print('The 2nd last price: ', prices[-2] )"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "The index can also be used to overwrite an item in the list:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[1.23, 1.98, 1.45, 1.67, 2.4, 1.89]\n",
      "[2.41, 1.98, 1.45, 1.67, 2.4, 0.99]\n"
     ]
    }
   ],
   "source": [
    "print(prices)\n",
    "prices[0] = 2.41\n",
    "prices[-1] = 0.99\n",
    "print(prices)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "You can also get a range of items from a list:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[1.98, 1.45, 1.67]\n"
     ]
    }
   ],
   "source": [
    "print(prices[1:4] )"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "This is called a 'slice'. Which indices from the prices list are included in this slice?  "
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## List Operations\n",
    "\n",
    "Lists have some built in functionality that makes them easier to work with.\n",
    "\n",
    "### Adding to / Removing from Lists"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['USA', 'UK', 'France', 'Germany', 'Spain']\n"
     ]
    }
   ],
   "source": [
    "countries = ['USA', 'UK', 'France', 'Germany']\n",
    "\n",
    "# adding on to the end of a list\n",
    "countries.append('Spain')\n",
    "print(countries)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['USA', 'UK', 'Australia', 'France', 'Germany', 'Spain']\n"
     ]
    }
   ],
   "source": [
    "# inserting into a specific index of a list\n",
    "countries.insert(2, 'Australia')\n",
    "print(countries)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['USA', 'UK', 'Australia', 'Germany', 'Spain']\n"
     ]
    }
   ],
   "source": [
    "# removing from a specific index\n",
    "countries.pop(3)\n",
    "print(countries)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['USA', 'UK', 'Australia', 'Spain']\n"
     ]
    }
   ],
   "source": [
    "# removing a particular value from a list\n",
    "countries.remove('Germany')\n",
    "print(countries)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Examining Lists"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "True\n",
      "False\n"
     ]
    }
   ],
   "source": [
    "primes = [2,3,5,7,11,13]\n",
    "\n",
    "# check if a value is in a list\n",
    "print(3 in primes)\n",
    "print(4 in primes)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2\n"
     ]
    }
   ],
   "source": [
    "# find the index of a value in a list\n",
    "print(primes.index(5))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "minimum: 2\n",
      "maximum: 13\n",
      "sum: 41\n"
     ]
    }
   ],
   "source": [
    "# find the minimum, maximum, and sum\n",
    "print('minimum:', min(primes))\n",
    "print('maximum:', max(primes))\n",
    "print('sum:', sum(primes))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Other List Operations\n",
    "\n",
    "The addition and multiplication operators also work on lists:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {
    "scrolled": true
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[18, 22, 21, 32, 12, 11, 16, 18]\n",
      "[18, 22, 21, 32, 18, 22, 21, 32]\n"
     ]
    }
   ],
   "source": [
    "print(quantities1 + quantities2)\n",
    "print(quantities1 * 2)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Exercise\n",
    "\n",
    "Python allows you to have lists containing multiple different types of variable, as in the below example. Try to transform this list into: [1,2,3] using the operations you've learned."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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