Electronic mail
===============

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

#. Write the function :py:func:`address1` that takes a first name
   and a last name (strings), and returns an e-mail address following the
   pattern: ``first.last@student.upc.edu``. Examples:
   
   .. literalinclude:: test-emails1.txt
      :language: python3
      :lines: 3-

   .. note::
      More tests are provided in the :download:`test-emails1.txt<test-emails1.txt>` file.
      
#. Write the function :py:func:`address2` that takes a first name
   and a last name (strings), and returns an e-mail address following the
   pattern seen in the previous exercice but with a maximum of 10
   characters allowed for the first name and a maximum of 15
   characters for the last name (in both cases the first characters
   will be selected). Examples:
   
   .. literalinclude:: test-emails2.txt
      :language: python3
      :lines: 3-

   .. note::
      More tests are provided in the :download:`test-emails2.txt<test-emails2.txt>` file.
   
#. Write the function :py:func:`valid_address` that takes an e-mail
   address (string), and returns ``True`` if it is a valid address and
   ``False`` otherwise. A string represents a valid address if it
   contains one and only one '@' symbol and there are at least 2
   characters on the left of the '@' symbol. Examples:
             
   .. literalinclude:: test-emails3.txt
      :language: python3
      :lines: 3-

   .. note::
      More tests are provided in the :download:`test-emails3.txt<test-emails3.txt>` file.

#. Write the function :py:func:`generate_password` that takes a
   first name, a last name and a dni (3 strings), and returns a password with
   the first three characters of the first name, then the first three
   characters of the last name and the two last digits of the dni. Examples:

   .. literalinclude:: test-emails4.txt
      :language: python3
      :lines: 3-

   .. note::
      More tests are provided in the :download:`test-emails4.txt<test-emails4.txt>` file.
      
.. rubric:: Solutions

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