Salespeople
===========

Vendor sales data for a company is represented as a list where each
element is a sublist that contains the information of a specific
seller: its identifier (integer), working area (string) and sales
figure (integer). A salesperson is assigned to a unique area and
therefore a sales identifier will appear in the list at most
once. For instance, the following list represents the data for 4
salespeople:

.. code:: python

        [[1182,'EMEA',1302], [1173,'AMS',1372], [1190,'EMEA',232], [1107,'AMS',173]]

Save the following functions into the file ``sales.py``.
	
#. Write the function :py:func:`below_threshold` that takes a list as
   described and a threshold sales figure, *s*, and returns the
   identifier corresponding to the first salesperson with a sales
   figure below *s*. If there is not such salesperson, the function
   must return the value -1.

   See the following examples:
   
   .. literalinclude:: sales1.txt
      :language: python3
      :lines: 3-

   .. note::

      More tests are provided in the file :download:`sales1.txt <sales1.txt>`

#. Write the function :py:func:`delete_id` that takes a list as
   described and an identifier, and returns a new list without the
   sublist corresponding to the salesperson with the given
   identifier. If there is not such salesperson, the function must
   return a list equal to the given one.

   See the following examples:
   
   .. literalinclude:: sales2.txt
      :language: python3
      :lines: 3-

   .. note::

      More tests are provided in the file :download:`sales2.txt <sales2.txt>`

#. Write the function :py:func:`drastic_policy` that takes a list as
   described and a threshold sales figure, *s*, and returns a new list
   without the sublist corresponding to the first salesperson with a
   sales figure below *s*. If there is no such salesperson, the
   function must return a list equal to the given one. This function
   must call the two previous ones.

   See the following examples:
   
   .. literalinclude:: sales3.txt
      :language: python3
      :lines: 3-


   .. note::

      More tests are provided in the file :download:`sales3.txt <sales3.txt>`

.. rubric:: Solution
      
A solution of these functions is provided in the file :download:`sales.py <solutions/sales.py>`.