Dictionaries adventure

py101/dictionaries/README.es.rst

@@ -1,14 +1,85 @@
-Boilerplate
------------
+Diccionarios
+------------
 
-Insertar alguna introducción aquí.
+Un diccionario es un tipo de datos similar a las listas, pero funciona
+asociando claves y valores en en vez de usar índices. Cada valor del
+diccionario puede ser accedido usando una clave que puede ser cualquier tipo
+ de objeto. Por ejemplo se pueden usar cadenas para referenciar objetos del
+ diccionario. Una pequeña base de datos telefónica puede ser almacenada usando
+ diccionarios de la siguiente manera
 
 .. sourcecode:: python
 
- print('Some python code here')
+ directorio = {}
+ directorio["Alex"] = '2203-3434'
+ directorio["Rick"] = '+543 3232320'
+ directorio["Rolling"] = '9476-62781'
+
+De manera alternativa, un diccionario puede ser inicializado usando la
+siguiente notación
+
+.. sourcecode:: python
+
+ edades = {
+ 'Alex': 23,
+ 'Rick': 42,
+ 'Rolling' : "No lo sé"
+ }
+
+Iteración
+---------
+
+Los diccionarios permiten ser iterados. Para iterar sobre las claves del
+diccionario se usa la siguiente sintaxis.
+
+.. sourcecode:: python
+
+ for name in ages:
+ print("Edad de {{}} es {{}}".format(name, ages[name]))
+
+El ejemplo va a imprimir algo similar a:
+
+.. sourcecode::
+
+ Edad de Rick es 42
+ Edad de Rolling es No lo sé
+ Edad de Alex es 23
+
+Sin embargo, un diccionario no mantiene el orden de los elementos almacenado
+ en él.
+
+Borrado de claves
+-----------------
+
+Para borrar un índice específico usa la palabra clave "del" como se muestra
+en el siguiente ejemplo:
+
+.. sourcecode:: python
+
+ ages = {
+ 'Alex': 39,
+ 'Rick': 42,
+ 'Rolling' : "I don't know"
+ }
+ del ages['Rolling']
+ print(ages) # imprime {'Rick': 42, 'Alex': 39}
 
 
 Desafío
 -------
 
-Describir el desafío aquí.
+Modifica el programa provisto abajo para que la función
+"print_only_even_keys", imprima solamente los nombres de aquellas claves
+cuyos valores son números pares.
+
+.. sourcecode:: python
+
+ def print_only_even_keys(some_dict):
+ # pon tu código aquí
+ pass
+
+ # no modifiques este código
+ print_only_even_keys({ 'Alfred': 28, 'Mary': 29 })
+ print_only_even_keys({ 'Alfred': 31, 'Mary': 29 })
+
+

py101/dictionaries/README.rst

@@ -1,14 +1,84 @@
-Boilerplate
+Dictonaries
 -----------
 
-Insert some introduction here.
+A dictionary is a data type similar to lists, but works with keys and
+values instead of indexes. Each value stored in a dictionary can be accessed
+using a key, which is any type of object, for example strings
+instead of using its index to address it.
+
+For example, a database of phone numbers could be stored using a dictionary
+like this:
+
+.. sourcecode:: python
+
+ phonebook = {}
+ phonebook["Alex"] = '2203-3434'
+ phonebook["Rick"] = '+543 3232320'
+ phonebook["Rolling"] = '9476-62781'
+
+Alternatively, a dictionary can be initialized using the following notation:
+
+.. sourcecode:: python
+
+ ages = {
+ 'Alex': 23,
+ 'Rick': 42,
+ 'Rolling' : "I don't know"
+ }
+
+Iteration
+---------
+
+Dictionaries can be iterated over. To iterate over the dictionary keys, use
+ the following syntax:
+
+.. sourcecode:: python
+
+ for name in ages:
+ print("Age of {{}} is {{}}".format(name, ages[name]))
+
+The previous example will print something similar to
+
+.. sourcecode::
+
+ Age of Rick is 42
+ Age of Rolling is I don't know
+ Age of Alex is 23
+
+However, a dictionary, unlike a list, does not keep the order of the values
+stored in it.
+
+Key removal
+-----------
+
+To remove a specified index, use the "del" keyword as shown in the following
+example:
 
 .. sourcecode:: python
 
- print('Some python code here')
+ ages = {
+ 'Alex': 39,
+ 'Rick': 42,
+ 'Rolling' : "I don't know"
+ }
+ del ages['Rolling']
+ print(ages) # prints {'Rick': 42, 'Alex': 39}
 
 
 Challenge
 ---------
 
-Describe the challenge here
+Modify the program below, so the "print_only_even_keys" function prints
+ only the name of the keys whose values are even numbers
+
+.. sourcecode:: python
+
+ def print_only_even_keys(some_dict):
+ # put your code here
+ pass
+
+ # Don't modify this code
+ print_only_even_keys({ 'Alfred': 28, 'Mary': 29 })
+ print_only_even_keys({ 'Alfred': 31, 'María': 29 })
+
+The program should Output "Alfred" in the first line and nothing else

py101/dictionaries/SOLUTION.rst

@@ -1,3 +1,9 @@
 .. sourcecode:: python
 
- print('Some solution here')
+def print_only_even_keys(some_dict):
+ for key in some_dict:
+ if some_dict[key] % 2 == 0:
+ print(key)
+
+print_only_even_keys({ 'Alfred': 28, 'Mary': 29 })
+print_only_even_keys({ 'Alfred': 31, 'Mary': 29 })

py101/dictionaries/__init__.py

@@ -31,10 +31,17 @@ def tearDown(self):
  def runTest(self):
  """Makes a simple test of the output"""
 
- # code = compile(self.candidate_code, self.file_name, 'exec',
- # optimize=0)
- # exec(code)
- self.fail("Test not implemented")
+
+ code = compile(self.candidate_code, self.file_name, 'exec', optimize=0)
+
+ self.assertIn('print_only_even_keys',
+ code.co_names,
+ 'Should have the print_only_even_keys function defined')
+ eval(code)
+
+ self.assertMultiLineEqual("Alfred\n",
+ self.__mockstdout.getvalue(),
+ "Should have the same output")
 
 
 class Adventure(BaseAdventure):

tests/test_story.py

@@ -10,6 +10,7 @@
 import py101.loops
 import py101.functions
 import py101.classes
+import py101.dictionaries
 import unittest
 
 
@@ -101,6 +102,17 @@ def description(self):
 
 print(car1.description())
 print(car2.description())"""
+ ),
+ AdventureData(
+ py101.dictionaries,
+ """def print_only_even_keys(some_dict):
+ for key in some_dict:
+ if some_dict[key] % 2 == 0:
+ print(key)
+
+print_only_even_keys({ 'Alfred': 28, 'Mary': 29 })
+print_only_even_keys({ 'Alfred': 31, 'Mary': 29 })
+"""
  )
 ]