clarifications on the sum_series assignment

Author: PythonCHB

source/exercises/fib_and_lucas.rst

@@ -12,12 +12,15 @@ Goal:
 
 The `Fibonacci Series`_ is a numeric series starting with the integers 0 and 1.
 
-In this series, the next integer is determined by summing the previous two.
+In this series, the next integer is determined by summing the previous two
+
 
 This gives us::
 
     0, 1, 1, 2, 3, 5, 8, 13, ...
 
+.. note: 0+1 is 1; 1+1 is 2; 1+2 is 3; 2+3 is 5; 3+5 is 8; and so on forever...
+
 We will write a function that computes this series -- then generalize it.
 
 .. _Fibonacci Series: http://en.wikipedia.org/wiki/Fibbonaci_Series
@@ -31,12 +34,11 @@ Step 1
 
   - The function should have one parameter ``n``.
 
-  - The function should return the ``nth`` value in the fibonacci series
-    (starting with zero index).
+  - The function should return the ``nth`` value in the fibonacci series (starting with zero index).
 
 * Ensure that your function has a well-formed ``docstring``
 
-Note that the fibinacci series is naturally recursive -- the value is
+Note that the fibonacci series is naturally recursive -- the value is
 defined by previous values:
 
 fib(n) = fib(n-2) + fib(n-1)
@@ -58,50 +60,58 @@ In your ``series.py`` module, add a new function ``lucas`` that returns the
 
 Ensure that your function has a well-formed ``docstring``
 
+YOu should find it's *very* similar to the ``fibonacci()`` function.
+
 Generalizing
 ------------
 
-Both the *fibonacci series* and the *lucas numbers* are based on an identical
-formula.
+Both the *fibonacci series* and the *lucas numbers* are based on an identical formula:
+
+fib(n) = fib(n-2) + fib(n-1)
+
+That's why the code is so similar.
+
+This formula creates a class of series that are all related -- each with a different two starting numbers.
+
+Add a third function called ``sum_series`` that can compute all of these related series.
+
+It should have one required parameter and two optional parameters.
+The required parameter will determine which element in the
+series to print.
+The two optional parameters will have default values of 0 and 1 and will determine the first two values for the series to be produced.
+
+Calling this function with no optional parameters will produce numbers from the *fibonacci series* (because 0 and 1 are the defaults).
 
-Add a third function called ``sum_series`` with one required parameter and two
-optional parameters. The required parameter will determine which element in the
-series to print. The two optional parameters will have default values of 0 and
-1 and will determine the first two values for the series to be produced.
+Calling it with the optional arguments 2 and 1 will
+produce values from the *lucas numbers*.
 
-Calling this function with no optional parameters will produce numbers from the
-*fibonacci series*.  Calling it with the optional arguments 2 and 1 will
-produce values from the *lucas numbers*. Other values for the optional
-parameters will produce other series.
+Other values for the optional parameters will produce other series.
 
 **Note:** While you *could* check the input arguments, and then call one
 of the functions you wrote, the idea of this exercise is to make a general
-function, rather than one specialized. So you should reimplement the code
+function, rather than one specialized. So you should re-implement the code
 in this function.
 
-In fact, you could go back and reimplement your fibonacci and lucas
-functions to call this one with particular arguments.
+In fact, you could go back and re-implement your fibonacci and lucas
+functions to call ``sum-series`` with particular arguments.
 
 Ensure that your function has a well-formed ``docstring``
 
 Tests...
 --------
 
-Add a block of code to the end of your ``series.py``
-module. Use the block to write a series of ``assert`` statements that
+Add a block of code to the end of your ``series.py`` module.
+Use the block to write a series of ``assert`` statements that
 demonstrate that your three functions work properly.
 
 Use comments in this block to inform the observer what your tests do.
 
-We have created a template for you to use, to clarify what we mean by these
-tests:
+We have created a template for you to use to clarify what we mean by these asserts:
 
 :download:`series_template.py <../exercises/series_template.py>`
 
-Add your new module to your git clone and commit frequently while working on
-your implementation. Include good commit messages that explain concisely both
-*what* you are doing and *why*.
+Add your new module to your personal git repo and commit frequently while working on your implementation.
+Include good commit messages that explain concisely both *what* you are doing and *why*.
 
-When you are finished, push your changes to your fork of the class repository
-in GitHub and make a pull request.
+When you are finished, push your changes to your fork of the class repository in GitHub and make a pull request.
 

source/solutions/Lesson02/print_grid.py

@@ -14,6 +14,9 @@
 def print_grid_trivial():
     """
     Did anyone come up with the most trivial possible solution?
+
+    Note that this may the the wy to go, oif this all you need to do:
+      print something specific once. Why write fancy code for that?
     """
     print("""
 + - - - - + - - - - +