Marathon
========

The results of marathon races are stored in files with the following
structure: the first line contains a header detailing the meaning of
each data field in the file and the following lines correspond to a
participant each and have the following data fields: surname
(:class:`str`), racing time (hours, minutes and seconds, three
integers (:class:`int`)) and country (:class:`str`), separated by a
space. File :download:`marathon.txt<examples/marathon.txt>` is an
example of this kind of files, with the following content:

.. literalinclude:: examples/marathon.txt
   :language: console

Save the following functions into file ``marathon.py``.
	      
#. Write the function :py:func:`convert` that given the name of a file
   with the results of a marathon (:class:`str`), returns a
   :class:`list` of tuples (:class:`tuple`) where each tuple
   corresponds to a participant and contains the surname
   (:class:`str`), the racing time *converted to seconds*
   (:class:`int`) and the country (:class:`str`). Participants in this
   list must be in the same order as the file. Example:
   
   .. literalinclude:: test-convert.txt
      :language: python3
      :lines: 3-

   .. note::

      More tests are provided in file :download:`test-convert.txt`
  
#. Write the function :py:func:`time_under` that given a :class:`list`
   of tuples (:class:`tuple`) such as that returned by function
   :py:func:`convert` and a time, ``t``, in seconds (:class:`int`),
   returns ``True`` if there is at least one runner that has made a
   time below ``t``, and ``False`` otherwise. Example:
   
   .. literalinclude:: test-time_under.txt
      :language: python3
      :lines: 3-

   .. note::

      More tests are provided in file :download:`test-time_under.txt`
  
#. Write the function :py:func:`first_difference` that given
   :class:`list` of tuples (:class:`tuple`) as that returned by function
   :py:func:`convert` and the name of a file (:class:`str`), creates a
   file with the given name where each line represents one runner and
   includes the surname (:class:`str`) and the time difference with the
   first classified, in seconds (:class:`int`), separated by a space. We
   can suppose that the given list is sorted increasingly by time. The
   first runner must also appear in the file with a time difference
   of 0. Examples:

   .. literalinclude:: test-first_difference.txt
      :language: python3
      :lines: 3-

   .. note::

      More tests are provided in file :download:`test-first_difference.txt`
  
.. rubric:: Solutions

A solution of these functions is provided in file :download:`marathon.py <solutions/marathon.py>`