In order to compile and run the examples included in this book, you will require the following software:

• Python Version 3.7 or higher, with the standard suite of libraries:
  
  • We'll use mypy to check type hints (http://mypy-lang.org).
• We'll take a look at these additional packages:
  • PyYAML (http://pyyaml.org).
    
  • SQLAlchemy (http://www.sqlalchemy.org): When building this, check the installation guide carefully. In particular, refer to https://docs.sqlalchemy.org/en/12/intro.html#installing-the-c-extensions for information on simplifying the installation by disabling the C extension.
    
  • Flask (http://flask.pocoo.org).
  • Requests (https://2.python-requests.org/en/master/).
  • Jinja (http://jinja.pocoo.org/).
  • PyTest (https://docs.pytest.org/en/latest/).
  • Sphinx (http://sphinx-doc.org).
• Optionally, you might want to use the Black tool to format your code consistently (https://black.readthedocs.io/en/stable/).
• Additionally, the overall test suite for this book's code is run using the tox tool (https://tox.readthedocs.io/en/latest/).

You can download the example code files for this book from your account at www.packt.com. If you purchased this book elsewhere, you can visit www.packt.com/support and register to have the files emailed directly to you.

You can download the code files by following these steps:

1. Log in or register at www.packt.com.
2. Select the SUPPORT tab.
3. Click on Code Downloads & Errata.
4. Enter the name of the book in the Search box and follow the onscreen instructions.

Once the file is downloaded, please make sure that you unzip or extract the folder using the latest version of the following:

• WinRAR/7-Zip for Windows
• Zipeg/iZip/UnRarX for Mac
• 7-Zip/PeaZip for Linux

The code bundle for the book is also hosted on GitHub at https://github.com/PacktPublishing/Mastering-Object-Oriented-Python-Second-Edition. In case there's an update to the code, it will be updated on the existing GitHub repository.

We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

Visit the following link to see the code being executed:

http://bit.ly/2XIu8Tk

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "Mount the downloaded WebStorm-10*.dmg disk image file as another disk in your system."

A block of code is set as follows:

def F(n: int) -> int:
    if n in (0, 1):
        return 1
    else:
        return F(n-1) + F(n-2)

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

def factorial(n: int) -> int:
    """Compute n! recursively.

    :param n: an integer >= 0
    :returns: n!

    Because of Python's stack limitation, this won't
    compute a value larger than about 1000!.

    >>> factorial(5)
    120
    """

Any command-line input or output is written as follows:

$ python3 -m pip install --upgrade pip
$ python3 -m pip install black

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "Select System info from the Administration panel."