Clothes Shop
============

A clothing manufacturing company uses a *stock dictionary* for each
shop. In this dictionary (:class:`dict`), each key is a
3-:class:`tuple` with the code, size and color of a model of a piece
of clothing (3 :class:`str`) and the value is the number of pieces of
this model that are in the shop (:class:`int`).

Save all functions into the same file named ``clotheshop.py``.

#. Write the **modifier** function :py:func:`stock_increase` that
   given a stock dictionary, the code (:class:`str`), size
   (:class:`str`) and color (:class:`str`) of a model, and a number of
   pieces of this model(:class:`int`), **modifies** the dictionary adding
   this quantity to the given model.

   .. literalinclude:: test-shop1.txt
      :language: python3
      :lines: 3-
	      
   .. note::

      More tests are provided in :download:`test-shop1.txt <test-shop1.txt>`

#. Write the **modifier** function :py:func:`stock_decrease` that
   given a stock dictionary, the code (:class:`str`), size
   (:class:`str`) and color (:class:`str`) of a model, and a number of
   pieces of this model (:class:`int`), **modifies** the dictionary subtracting
   this quantity to the given model. We will suppose that there are
   always enough pieces to subtract the given quantity.

   .. literalinclude:: test-shop2.txt
      :language: python3
      :lines: 3-

   .. note::

      More tests are provided in  :download:`test-shop2.txt <test-shop2.txt>`
   
#. Write the function :py:func:`low_stock` that given a stock
   dictionary and a threshold (:class:`int`), returns a :class:`list`
   with those pieces with a stock lower than the given threshold. Each
   piece in the returnes list is represented with a tuple with the
   code, size and color.

   .. literalinclude:: test-shop3.txt
      :language: python3
      :lines: 3-

   .. note::

      More tests are provided in  :download:`test-shop3.txt <test-shop3.txt>`

#. A *sales list* is a nested list. Each sublist of it has the code,
   color and size of a model (3 :class:`str`) and the number of sold
   pieces of this model (:class:`int`). A *restocking list* is similar
   to a sales list but the amount means the number of restoked models.
   Write the **modifier** function :py:func:`update_stock` that given
   a stock dictionary, a sales list, and a restocking list,
   **modifies** the dictionary subtracting those sales of the first list
   and adding the restock of the second one. 
   
   This function must use the previous functions :py:func:`stock_increase` and
   py:func:`stock_decrease`.


   .. literalinclude:: test-shop4.txt
      :language: python3
      :lines: 3-

   .. note::

      More tests are provided in  :download:`test-shop4.txt <test-shop4.txt>`

.. rubric:: Solutions
      
A solution is provided in the :download:`clotheshop.py <solutions/clotheshop.py>`.