Links and renumbering

Notes/04_Classes_objects/01_Class.md

@@ -110,7 +110,7 @@ If you want to operate on an instance, you always have to refer too it explicitl
 
 ## Exercises
 
-### (a) Objects as Data Structures
+### Exercise 4.1: Objects as Data Structures
 
 In section 2 and 3, we worked with data represented as tuples and dictionaries.
 For example, a holding of stock could be represented as a tuple like this:
@@ -182,7 +182,7 @@ dictionary, just with somewhat different syntax.
 For example, instead of writing `s['name']` or `s['price']`, you now
 write `s.name` and `s.price`.
 
-### (b) Reading Data into a List of Objects
+### Exercise 4.2: Reading Data into a List of Objects
 
 In your `stock.py` program, write a function
 `read_portfolio(filename)` that reads portfolio data from a file into
@@ -226,7 +226,7 @@ Try a list comprehension:
 
 Again, notice the similarity between `Stock` objects and dictionaries. They’re basically the same idea, but the syntax for accessing values differs.
 
-### (c) Adding some Methods
+### Exercise 4.3: Adding some Methods
 
 With classes, you can attach functions to your objects.  These are
 known as methods and are functions that operate on the data stored
@@ -250,4 +250,4 @@ work like this:
 >>>
 ```
 
-[Next](02_Inheritance)
+[Contents](../Contents) \| [Previous (3.6 Design discussion)](../03_Program_organization/06_Design_discussion) \| [Next (4.2 Inheritance)](02_Inheritance)

Notes/04_Classes_objects/02_Inheritance.md

@@ -220,7 +220,7 @@ We're not going to explore multiple inheritance further in this course.
 
 ## Exercises
 
-### (a) Print Portfolio
+### Exercise 4.4: Print Portfolio
 
 A major use of inheritance is in writing code that’s meant to be extended or customized in various ways—especially in libraries or frameworks.
 To illustrate, start by adding the following function to your `stock.py` program:
@@ -263,7 +263,7 @@ When you run your `stock.py`, you should get this output:
            IBM        100      70.44
 ```
 
-### (b) An Extensibility Problem
+### Exercise 4.5: An Extensibility Problem
 
 Suppose that you wanted to modify the `print_portfolio()` function to
 support a variety of different output formats such as plain-text,
@@ -329,7 +329,7 @@ if __name__ == '__main__':
 When you run this new code, your program will immediately crash with a `NotImplementedError` exception.
 That’s not too exciting, but continue to the next part.
 
-### (c) Using Inheritance to Produce Different Output
+### Exercise 4.6: Using Inheritance to Produce Different Output
 
 The `TableFormatter` class you defined in part (a) is meant to be extended via inheritance.
 In fact, that’s the whole idea. To illustrate, define a class `TextTableFormatter` like this:
@@ -430,7 +430,7 @@ Using a similar idea, define a class `HTMLTableFormatter` that produces a table
 
 Test your code by modifying the main program to create a `HTMLTableFormatter` object instead of a `CSVTableFormatter` object.
 
-### (d) Polymorphism in Action
+### Exercise 4.7: Polymorphism in Action
 
 A major feature of object-oriented programming is that you can plug an
 object into a program and it will work without having to change any of
@@ -499,4 +499,4 @@ That said, understanding what happened in this exercise will take you
 pretty far in terms of using most library modules and knowing
 what inheritance is good for (extensibility).
 
-[Next](03_Special_methods)
+[Contents](../Contents) \| [Previous (4.1 Classes)](01_Class) \| [Next (4.3 Special methods)](03_Special_methods)

Notes/04_Classes_objects/03_Special_methods.md

@@ -202,7 +202,7 @@ x = getattr(obj, 'x', None)
 
 ## Exercises
 
-### (a) Better output for printing objects
+### Exercise 4.8: Better output for printing objects
 
 All Python objects have two string representations.  The first
 representation is created by string conversion via `str()` (which is
@@ -248,7 +248,7 @@ See what happens when you read a portfolio of stocks and view the resulting list
 >>>
 ```
 
-### (b) An example of using `getattr()`
+### Exercise 4.9: An example of using `getattr()`
 
 In Exercise 4.2 you worked with a function `print_portfolio()` that made a table for a stock portfolio.
 That function was hard-coded to only work with stock data—-how limiting! You can do so much more if you use functions such as `getattr()`.
@@ -306,7 +306,7 @@ format.  Here’s how it should work:
 >>>
 ```
 
-### (c) Exercise Bonus: Column Formatting
+### Exercise 4.10: Exercise Bonus: Column Formatting
 
 Modify the `print_table()` function in part (B) so that it also
 accepts a list of format specifiers for formatting the contents of
@@ -329,4 +329,5 @@ each column.
 >>>
 ```
 
-[Next](04_Defining_exceptions)
+[Contents](../Contents) \| [Previous (4.2 Inheritance)](02_Inheritance) \| [Next (4.4 Exceptions)](04_Defining_exceptions)
+

Notes/04_Classes_objects/04_Defining_exceptions.md

@@ -22,7 +22,7 @@ class ProtocolError(NetworkError):
 
 ## Exercises
 
-### (a) Defining a custom exception
+### Exercise 4.11: Defining a custom exception
 
 It is often good practice for libraries to define their own exceptions.
 
@@ -47,3 +47,5 @@ Traceback (most recent call last):
 FormatError: Unknown table format xls
 >>>
 ```
+
+[Contents](../Contents) \| [Previous (4.3 Special methods)](03_Special_methods) \| [Next (5 Object Model)](../05_Object_model/00_Overview)