Append Reverse |2|
~~~~~~~~~~~~~~~~~~

For this question, you will be given an input file. The file will
consist of names and surnames of some people, with a space character
between a name and a surname. On each line, only 1 person’s name and
surname will be given. You should read the names and surnames from the
file and add them again at the bottom of the file in the reversed order,
i.e., “surname name”. Write a function named *append_reverse* which
takes an input *string* for the file name and returns a *list* of
*tuples* where each tuple consists of the name, surname pair you read
from the file.

The file will be ending with a newline character (\*:raw-latex:`\n*`),
so you don’t need to bother with that. This also lets you run your code
multiple times to double the person records in the file decently.

*Hint:* Check out the *string* method *split()*.

.. container:: sampleio

   Sample I/O:

.. |2| image:: ../../figures/difficulty_three.png
   :class: difficulty

.. code:: default

   Sample function call:  
       append_reverse("input.txt")  

   Content of the file "input.txt" before the function call:  
       Lewis Hamilton
       Nicholas Latifi
       Charles Leclerc
       Esteban Ocon
       Kimi Raikkonen

   Return value:
       [('Lewis', 'Hamilton'), ('Nicholas', 'Latifi'), ('Charles', 'Leclerc'), ('Esteban', 'Ocon'), ('Kimi', 'Raikkonen')]

   Content of the file "input.txt" after the function call:  
       Lewis Hamilton
       Nicholas Latifi
       Charles Leclerc
       Esteban Ocon
       Kimi Raikkonen
       Hamilton Lewis
       Latifi Nicholas
       Leclerc Charles
       Ocon Esteban
       Raikkonen Kimi

.. raw:: html

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Show the Answer

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.. raw:: html

   <div class="hiddenanswer">

.. code:: python

   def append_reverse(input_file_name):
       person_list = []
       input_file = open(input_file_name, "r")
       for line in input_file:
           name, surname = line.split()
           # Save as a tuple
           person_list.append((name, surname))

       input_file.close()
       # Re-open in append mode
       input_file = open(input_file_name, "a")
       for person in person_list:
           # first is name, second is surname
           string_to_write = person[1] + " " + person[0] + "\n"
           input_file.write(string_to_write)

       input_file.close()
       return person_list

.. raw:: html

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