Read a File
===========

* files are `strings` that are stored on `disk`
* we normally access them by using a `path` which describes their location
* to work with the strings inside we use the :py:func:`open` function:

.. doctest::

    >>> path = 'trivia/questions.csv'
    >>> file_handle = open( path, 'r')
    >>> file_handle
    <_io.TextIOWrapper name='trivia/questions.csv' mode='r' encoding='UTF-8'>

* we can treat a file like a `list` of lines (in some ways)

    >>> for line in file_handle:
    ...    print(repr(line))
    'What is RAM?|Memory|Female Sheep|Baby Sheep|Forgotten Sheep\n'
    'What is Python?|Language|Poisonous Snake|French Comedy Troupe|Quebecois Comedy Troupe\n'
    'How many bits in a byte?|8|32|64|4|2|10|100\n'
    'Who was the first Prime Minister of Canada?|Sir John Alexander Macdonald|Lester B. Pearson|Guglielmo Marconi|Avril Lavigne|Pierre Elliott Trudeau\n'
    ...
    >>> for line in file_handle:
    ...    print(repr(line))
    >>> # HUH? why not?

* the file has a `position` and as you `iterate` over it that position moves through the file

  * once you reach the end of the file, you can't (easily) re-iterate over it

.. note::

    :py:func:`repr` produces a code-like "representation" of an object,
    we use it here so that we can see what the resulting object is clearly.

Exercise: Iterate Over a File
------------------------------

* Create a new script that opens your `questions.txt` file and prints every line
* Why are there blank lines?
* Modify your script to *not* show blank lines (hint :doc:`stringmanipulation`)