Week6/openSAP_python1_Week_6_Unit_1_libraries_notebook.ipynb

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    "# Libraries\n",
    "This week focuses on the usage of libraries. Before learning how to use libraries it is first important to understand\n",
    "why libraries are necessary. \n",
    "\n",
    "\n",
    "## Motivation\n",
    "So far, our Python 🐍 programs only consist of a single file. In reality however, this leads to a number of problems. To\n",
    "mention just two:\n",
    "- Large programs in a single file quickly become confusing and difficult to maintain\n",
    "- No possibility to reuse existing functionality across programs besides copying source code\n",
    "\n",
    "Copying of program code itself leads to a maintainability problem. For example, how can a bug in the copied source code\n",
    "be fixed? How can we identify all the programs to which a particular piece of source code has been copied?  \n",
    "To circumvent these and a large number of further problems, programs in the real world are divided into small units,\n",
    "called modules. This modularization is an important principle when developing complex programs.\n",
    "\n",
    "\n",
    "## Modularization\n",
    "Not only programs but also other systems consist of independent components or modules. As an example think of an\n",
    "electric car. A electric car may consist of the following modules:\n",
    "- Chassis\n",
    "- Electric engines\n",
    "- Battery\n",
    "- Wheels\n",
    "- Entertainment system\n",
    "- Sensor for autonomous driving\n",
    "\n",
    "Each of these modules itself may consist of smaller modules. For example the entertainment system might consist of\n",
    "- a touch screen\n",
    "- speakers\n",
    "- a computer system\n",
    "- entertainment software\n",
    "\n",
    "The advantages of this modular approach a manifold. To name just a few:\n",
    "- Modules can be created and tested independently of the overall system\n",
    "- Modules can be reused in other products (e.g. other car models of the same manufacturer)\n",
    "- Modules can be exchanged upon failure\n",
    "- Modules can be exchanged for improved versions (e.g. a battery with improved capacity)\n",
    "\n",
    "\n",
    "### Modularization of software\n",
    "\n",
    "Software systems are among the most\n",
    "[complex systems](https://informationisbeautiful.net/visualizations/million-lines-of-code/) created by humans. \n",
    "For this reason modularization and abstraction play an important role when creating software.\n",
    "\n",
    "A low level approach for modularization is the usage of functions. As mentioned in the units about functions a function:\n",
    "- has a clear task\n",
    "- can be developed and tested independently of other functions\n",
    "- provides an abstraction of the implementation details (i.e. we do not need to know about the implementation details of\n",
    "  the `print` function in order to use it)\n",
    "\n",
    "Functions do not offer a possibility for reuse across different programs. This is where libraries come into the picture.\n",
    "Several related functions, e.g. related to statistics or creating user interfaces can be grouped together into a *library*. This\n",
    "library can then be reused across programs.\n",
    "\n",
    "\n",
    "## Libraries in Python\n",
    "\n",
    "In Python 🐍 there are two important sets of libraries. \n",
    "\n",
    "First, the [Python Standard Library](https://docs.python.org/3/library/index.html) is an integrated part of the Python\n",
    "programming language. The Python Standard Library defines, for example, the\n",
    "[numeric data types](https://docs.python.org/3/library/stdtypes.html#numeric-types-int-float-complex)\n",
    "`int` and `float` or basic [mathematical functions](https://docs.python.org/3/library/math.html).\n",
    "In order to effectively work with Python 🐍 it is important to learn to read the documentation of the\n",
    "[Python Standard Library](https://docs.python.org/3/library/index.html). Furthermore, it is useful to have a general\n",
    "overview of what kind of functionality is available in it.\n",
    "\n",
    "Second, the Python 🐍 ecosystem offers a large number of freely available libraries. For example, the\n",
    "[SciPy](https://pypi.org/project/scipy/) library provides functionality for mathematics, science, and engineering,\n",
    "[Flask](https://pypi.org/project/Flask/) is a library for building web applications and\n",
    "[FastAPI](https://pypi.org/project/fastapi/) can be used to build APIs using Python. The [Python Package Index](https://pypi.org/)\n",
    "and search engines are good starting points when searching for a library offering a particular functionality. "
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   "source": [
    "# Self Test"
   ]
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   "source": [
    "### Question 1\n",
    "`1.0 Pts`\n",
    "\n",
    "In the notebook to this unit, a link to complex systems is given. According to this link, which of the following objects is most complex in terms of lines of code?\n",
    "\n",
    "Average high-end car *(100 million)* \n",
    "\n",
    "The Large Hadron Collider *(50 million)* \n",
    "\n",
    "Space Shuttle - *(400 thousand)* \n",
    "\n",
    "Microsoft Office 2013 - *(45 million)*"
   ]
  }
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