intro-to-python/09_mappings/07_review.ipynb

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   "source": [
    "# Chapter 9: Mappings & Sets (Review Questions)"
   ]
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   "source": [
    "The questions below assume that you have read the [first <img height=\"12\" style=\"display: inline-block\" src=\"../static/link/to_nb.png\">](https://nbviewer.jupyter.org/github/webartifex/intro-to-python/blob/main/09_mappings/00_content.ipynb), [second <img height=\"12\" style=\"display: inline-block\" src=\"../static/link/to_nb.png\">](https://nbviewer.jupyter.org/github/webartifex/intro-to-python/blob/main/09_mappings/02_content.ipynb), and [third <img height=\"12\" style=\"display: inline-block\" src=\"../static/link/to_nb.png\">](https://nbviewer.jupyter.org/github/webartifex/intro-to-python/blob/main/09_mappings/04_content.ipynb) part of Chapter 9.\n",
    "\n",
    "Be concise in your answers! Most questions can be answered in *one* sentence."
   ]
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   "source": [
    "## Essay Questions "
   ]
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   "source": [
    "**Q1**: `dict` objects are well-suited **to model** discrete mathematical **functions** and to approximate continuous ones. What property of dictionaries is the basis for that claim, and how does it relate to functions in the mathematical sense?"
   ]
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   "source": [
    " < your answer >"
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   "source": [
    "**Q2**: Explain why **hash tables** are  a **trade-off** between **computational speed** and **memory** usage!"
   ]
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   "cell_type": "markdown",
   "metadata": {},
   "source": [
    " < your answer >"
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   "source": [
    "**Q3:** The `dict` type is an **iterable** that **contains** a **finite** number of key-value pairs. Despite that, why is it *not* considered a **sequence**?"
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   "source": [
    " < your answer >"
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   "source": [
    "**Q4**: Whereas *key* **look-ups** in a `dict` object run in so-called **[constant time <img height=\"12\" style=\"display: inline-block\" src=\"../static/link/to_wiki.png\">](https://en.wikipedia.org/wiki/Time_complexity#Constant_time)** (i.e., *extremely* fast), that does not hold for *reverse* look-ups. Why is that?"
   ]
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   "cell_type": "markdown",
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   "source": [
    " < your answer >"
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  {
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   "source": [
    "**Q5**: Why is it conceptually correct that the Python core developers do not implement **slicing** with the `[]` operator for `dict` objects?"
   ]
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   "cell_type": "markdown",
   "metadata": {},
   "source": [
    " < your answer >"
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   "source": [
    "**Q6**: **Memoization** is an essential concept to know to solve problems in the real world. Together with the idea of **recursion**, it enables us to solve problems in a \"backwards\" fashion *effectively*.\n",
    "\n",
    "Compare the **recursive** formulation of `fibonacci()` in [Chapter 9 <img height=\"12\" style=\"display: inline-block\" src=\"../static/link/to_nb.png\">](https://nbviewer.jupyter.org/github/webartifex/intro-to-python/blob/main/09_mappings/02_content.ipynb#\"Easy-at-second-Glance\"-Example:-Fibonacci-Numbers--(revisited)), the \"*Easy at second Glance*\" example, with the **iterative** version in [Chapter 4 <img height=\"12\" style=\"display: inline-block\" src=\"../static/link/to_nb.png\">](https://nbviewer.jupyter.org/github/webartifex/intro-to-python/blob/main/04_iteration/02_content.ipynb#\"Hard-at-first-Glance\"-Example:-Fibonacci-Numbers-%28revisited%29), the \"*Hard at first Glance*\" example!\n",
    "\n",
    "How are they similar and how do they differ? Also consider how the flow of execution behaves when the functions are being executed."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    " < your answer >"
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  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**Q7**: How are the `set` and the `dict` types related? How could we use the latter to mimic the former?"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    " < your answer >"
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   "metadata": {},
   "source": [
    "## True / False Questions"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Motivate your answer with *one short* sentence!"
   ]
  },
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   "source": [
    "**Q8**: We may *not* put `dict` objects inside other `dict` objects because they are **mutable**."
   ]
  },
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   "cell_type": "markdown",
   "metadata": {},
   "source": [
    " < your answer >"
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   "cell_type": "markdown",
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   "source": [
    "**Q9**: **Mutable** objects (e.g., `list`) may generally *not* be used as keys in a `dict` object. However, if we collect, for example, `list` objects in a `tuple` object, the composite object becomes **hashable**."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    " < your answer >"
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   "source": [
    "**Q10**: **Mutability** of a `dict` object works until the underlying hash table becomes too crowded. Then, we cannot insert any items any more making the `dict` object effectively **immutable**. Luckily, that almost never happens in practice."
   ]
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   "cell_type": "markdown",
   "metadata": {},
   "source": [
    " < your answer >"
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   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**Q11**: A `dict` object's [.update() <img height=\"12\" style=\"display: inline-block\" src=\"../static/link/to_py.png\">](https://docs.python.org/3/library/stdtypes.html#dict.update) method only inserts key-value pairs whose key is *not* yet in the `dict` object. So, it does *not* overwrite anything."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    " < your answer >"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**Q12**: The `set` type is both a mapping and a sequence."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    " < your answer >"
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