intro-to-python/03_conditionals_02_exercises.ipynb

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   "source": [
    "# Chapter 3: Conditionals & Exceptions"
   ]
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   "source": [
    "## Coding Exercises"
   ]
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   "source": [
    "The exercises below assume that you have read [Chapter 3](https://nbviewer.jupyter.org/github/webartifex/intro-to-python/blob/master/03_conditionals_00_lecture.ipynb) in the book.\n",
    "\n",
    "The `...`'s in the code cells indicate where you need to fill in code snippets. The number of `...`'s within a code cell give you a rough idea of how many lines of code are needed to solve the task. You should not need to create any additional code cells for your final solution. However, you may want to use temporary code cells to try out some ideas."
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   "source": [
    "### Discounting Customer Orders"
   ]
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    "**Q1.1**: Write a function `discounted_price()` that takes the positional arguments `unit_price` (of type `float`) and `quantity` (of type `int`) and implements a discount scheme for a line item in a customer order as follows:\n",
    "\n",
    "- if the unit price is over 100 dollars, grant 10% relative discount\n",
    "- if a customer orders more than 10 items, one in every five items is for free\n",
    "\n",
    "Only one of the two discounts is granted, whichever is better for the customer.\n",
    "\n",
    "The function should then return the overall price for the line item. Do not forget to round appropriately."
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    "def discounted_price(unit_price, quantity):\n",
    "    \"\"\"Calculate the price of a line item in an order.\n",
    "\n",
    "    Args:\n",
    "        unit_price (float): price of one ordered item\n",
    "        quantity (int): number of items ordered\n",
    "\n",
    "    Returns:\n",
    "        line_item_price (float)\n",
    "    \"\"\"\n",
    "    ...\n",
    "    ...\n",
    "    ...\n",
    "    ...\n",
    "\n",
    "    ...\n",
    "    ...\n",
    "    ...\n",
    "    ...\n",
    "    ...\n",
    "\n",
    "    return ..."
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   "source": [
    "**Q1.2**: Calculate the final price for the following line items of an order:\n",
    "- $7$ smartphones @ $99.00$ USD\n",
    "- $3$ workstations @ $999.00$ USD\n",
    "- $19$ GPUs @ $879.95$ USD\n",
    "- $14$ Raspberry Pis @ $35.00$ USD"
   ]
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  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "discounted_price(...)"
   ]
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  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "discounted_price(...)"
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  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "discounted_price(...)"
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  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "discounted_price(...)"
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   "cell_type": "markdown",
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   "source": [
    "**Q1.3**: Calculate the last two line items with order quantities of $20$ and $15$. What do you observe?"
   ]
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  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "discounted_price(...)"
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  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "discounted_price(...)"
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   "cell_type": "markdown",
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   "source": [
    " "
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   "cell_type": "markdown",
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   "source": [
    "**Q1.4**: Looking at the `if`-`else`-logic in the function, why do you think the four example line items in **Q1.2** were chosen as they were?"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    " < your answer >"
   ]
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   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Fizz Buzz"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "The kids game [Fizz Buzz](https://en.wikipedia.org/wiki/Fizz_buzz) is said to be often used in job interviews for entry-level positions. However, opinions vary as to how good of a test it is (cf., [source](https://news.ycombinator.com/item?id=16446774)).\n",
    "\n",
    "In its simplest form, a group of people starts counting upwards in an alternating fashion. Whenever a number is divisible by $3$, the person must say \"Fizz\" instead of the number. The same holds for numbers divisible by $5$ when the person must say \"Buzz.\" If a number is divisible by both numbers, one must say \"FizzBuzz.\" Probably, this game would also make a good drinking game with the \"right\" beverages."
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   "source": [
    "**Q2.1**: First, create a list `numbers` with the numbers from 1 through 100. You could type all numbers manually, but there is, of course, a smarter way. The built-in [range()](https://docs.python.org/3/library/functions.html#func-range) may be useful here. Read how it works in the documentation. To make the output of [range()](https://docs.python.org/3/library/functions.html#func-range) a `list` object, you have to wrap it with the [list()](https://docs.python.org/3/library/functions.html#func-list) built-in (i.e., `list(range(...))`)."
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    "numbers = ..."
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   "source": [
    "**Q2.2**: Loop over the `numbers` list and *replace* numbers for which one of the two (or both) conditions apply with text strings `\"Fizz\"`, `\"Buzz\"`, or `\"FizzBuzz\"` using the indexing operator `[]` and the assignment statement `=`.\n",
    "\n",
    "In [Chapter 1](https://nbviewer.jupyter.org/github/webartifex/intro-to-python/blob/master/01_elements_00_lecture.ipynb#Who-am-I?-And-how-many?), we saw that Python starts indexing with `0` as the first element. Keep that in mind.\n",
    "\n",
    "So in each iteration of the `for`-loop, you have to determine an `index` variable as well as check the actual `number` for its divisors.\n",
    "\n",
    "Hint: the order of the conditions is important!"
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    "for number in numbers:\n",
    "    ...\n",
    "\n",
    "    ...\n",
    "    ...\n",
    "    ...\n",
    "    ...\n",
    "    ...\n",
    "    ..."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**Q2.3**: Create a loop that prints out either the number or any of the Fizz Buzz substitutes. Do it in such a way that we do not end up with 100 lines of output here."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "for number in numbers:\n",
    "    print(...)"
   ]
  }
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