[Basics Concept/Lasagna Exercise]: Changed return keyword Examples (#…

…3689)

* Changed examples for use of the return keyword in Python functions.
See discussion at http://forum.exercism.org/t/missing-print-in-python-basics-functions-return/11025/4 for additonal information.

* Further massaging of examples and adding variable assignment example.

concepts/basics/about.md

@@ -109,7 +109,7 @@ Related functions and classes (_with their methods_) can be grouped together in
 
 The `def` keyword begins a [function definition][function definition].
 Each function can have zero or more formal [parameters][parameters] in `()` parenthesis, followed by a `:` colon.
-Statements for the _body_ of the function begin on the line following `def` and must be _indented in a block_.
+Statements for the _body_ of the function begin on the line following `def` and must be _indented in a block_:
 
 
 ```python
@@ -134,24 +134,55 @@ def add_two_numbers(number_one, number_two):
 IndentationError: unindent does not match any outer indentation level
 ```
 
-Functions _explicitly_ return a value or object via the [`return`][return] keyword.
-Functions that do not have an _explicit_ `return` expression will _implicitly_ return [`None`][none].
+
+Functions _explicitly_ return a value or object via the [`return`][return] keyword:
+
 
 ```python
-# Function definition on first line.
+# Function definition on first line, explicit return used on final line.
 def add_two_numbers(number_one, number_two):
-  result = number_one + number_two
-  return result  # Returns the sum of the numbers.
+  return number_one + number_two   
+
 
+# Calling the function in the Python terminal returns the sum of the numbers.
 >>> add_two_numbers(3, 4)
 7
 
-# This function will return None.
+# Assigning the function call to a variable and printing 
+# the variable will also return the value.
+>>> sum_with_return = add_two_numbers(5, 6)
+>>> print(sum_with_return)
+7
+```
+
+Functions that do not have an _explicit_ `return` expression will _implicitly_ return the [`None`][none] object.
+The details of `None` will be covered in a later exercise.
+For the purposes of this exercise and explanation, `None` is a placeholder that represents nothing, or null:
+
+
+```python
+# This function does not have an explicit return.
 def add_two_numbers(number_one, number_two):
   result = number_one + number_two
 
+
+# Calling the function in the Python terminal appears 
+# to not return anything at all.
+>>> add_two_numbers(5, 7)
+>>>
+
+
+# Using print() with the function call shows that 
+# the function is actually returning the **None** object.
 >>> print(add_two_numbers(5, 7))
 None
+
+
+# Assigning the function call to a variable and printing 
+# the variable will also show None.
+>>> sum_without_return = add_two_numbers(5, 6)
+>>> print(sum_without_return)
+None
 ```
 
 

concepts/basics/introduction.md

@@ -50,7 +50,7 @@ Statements for the _body_ of the function begin on the line following `def` and
 
 
 ```python
-# The body of a function is indented by 2 spaces, & prints the sum of the numbers.
+# The body of this function is indented by 2 spaces,& prints the sum of the numbers.
 def add_two_numbers(number_one, number_two):
   total = number_one + number_two
   print(total)  
@@ -71,24 +71,55 @@ def add_two_numbers(number_one, number_two):
 IndentationError: unindent does not match any outer indentation level
 ```
 
-Functions explicitly return a value or object via the [`return`][return] keyword.
-Functions that do not have an explicit `return` expression will _implicitly_ return [`None`][none].
+
+Functions _explicitly_ return a value or object via the [`return`][return] keyword:
+
 
 ```python
-# Function definition on first line.
+# Function definition on first line, explicit return used on final line.
 def add_two_numbers(number_one, number_two):
-  result = number_one + number_two
-  return result  # Returns the sum of the numbers.
+  return number_one + number_two   
+
 
+# Calling the function in the Python terminal returns the sum of the numbers.
 >>> add_two_numbers(3, 4)
 7
 
-# This function will return None.
+# Assigning the function call to a variable and printing 
+# the variable will also return the value.
+>>> sum_with_return = add_two_numbers(5, 6)
+>>> print(sum_with_return)
+7
+```
+
+Functions that do not have an _explicit_ `return` expression will _implicitly_ return the [`None`][none] object.
+The details of `None` will be covered in a later exercise.
+For the purposes of this exercise and explanation, `None` is a placeholder that represents nothing, or null:
+
+
+```python
+# This function does not have an explicit return.
 def add_two_numbers(number_one, number_two):
   result = number_one + number_two
 
+
+# Calling the function in the Python terminal appears 
+# to not return anything at all.
+>>> add_two_numbers(5, 7)
+>>>
+
+
+# Using print() with the function call shows that 
+# the function is actually returning the **None** object.
 >>> print(add_two_numbers(5, 7))
 None
+
+
+# Assigning the function call to a variable and printing 
+# the variable will also show None.
+>>> sum_without_return = add_two_numbers(5, 6)
+>>> print(sum_without_return)
+None
 ```
 
 

exercises/concept/guidos-gorgeous-lasagna/.docs/introduction.md

@@ -87,24 +87,55 @@ def add_two_numbers(number_one, number_two):
 IndentationError: unindent does not match any outer indentation level
 ```
 
-Functions explicitly return a value or object via the [`return`][return] keyword.
-Functions that do not have an _explicit_ `return` expression will _implicitly_ return [`None`][none].
+
+Functions _explicitly_ return a value or object via the [`return`][return] keyword:
 
 ```python
-# Function definition on first line.
+# Function definition on first line, explicit return used on final line.
 def add_two_numbers(number_one, number_two):
-  result = number_one + number_two
-  return result  # Returns the sum of the numbers.
+  return number_one + number_two   
 
+
+# Calling the function in the Python terminal returns the sum of the numbers.
 >>> add_two_numbers(3, 4)
 7
 
-# This function will return None.
+# Assigning the function call to a variable and printing 
+# the variable will also return the value.
+>>> sum_with_return = add_two_numbers(5, 6)
+>>> print(sum_with_return)
+7
+```
+
+
+Functions that do not have an _explicit_ `return` expression will _implicitly_ return the [`None`][none] object.
+The details of `None` will be covered in a later exercise.
+For the purposes of this exercise and explanation, `None` is a placeholder that represents nothing, or null:
+
+
+```python
+# This function does not have an explicit return.
 def add_two_numbers(number_one, number_two):
   result = number_one + number_two
 
+
+# Calling the function in the Python terminal appears 
+# to not return anything at all.
+>>> add_two_numbers(5, 7)
+>>>
+
+
+# Using print() with the function call shows that 
+# the function is actually returning the **None** object.
 >>> print(add_two_numbers(5, 7))
 None
+
+
+# Assigning the function call to a variable and printing 
+# the variable will also show None.
+>>> sum_without_return = add_two_numbers(5, 6)
+>>> print(sum_without_return)
+None
 ```