Fix broken links

Author: matusf

Exercises/README.md

@@ -13,18 +13,18 @@ This course requires the use of Python 3.6 or newer.  If you are
 using Python 2, most of the material still applies, but you will
 have to make minor code modifications here and there. 
 
-- link:PythonMastery.pdf[`PythonMastery.pdf`] is a PDF that contains
+- [`PythonMastery.pdf`](../PythonMastery.pdf) is a PDF that contains
 all of the presentation slides.
 
-- The link:Exercises/index.html[`Exercises/`] folder is where you
+- The [`Exercises/`](index.md) folder is where you
 find all the class exercises.
 
-- The `Data/` folder is where you find data files, scripts, and
+- The [`Data/`](../Data/) folder is where you find data files, scripts, and
 other files used by the exercises.
 
-- The `Solutions/` folder contains complete solution code for
+- The [`Solutions/`](../Solutions/) folder contains complete solution code for
 various exercises.  Each problem has its own directory.  For example,
-the solution to exercise 3.2 can be found in the `Solution/3_2/` directory.
+the solution to exercise 3.2 can be found in the [`Solutions/3_2/`](../Solutions/3_2/) directory.
 
 Every attempt has been made to make sure exercises work.  However, it's 
 possible that you will find typos or minor mistakes. If you find any

Exercises/ex2_3.md

@@ -310,7 +310,7 @@ you do need to make sure you don't go overboard with the syntax.
 
 ## (f) Saving a lot of memory
 
-In link:ex2_1.html[Exercise 2.1] you wrote a function
+In [Exercise 2.1](ex2_1.md) you wrote a function
 `read_rides_as_dicts()` that read the CTA bus data into a list of
 dictionaries.  Using it requires a lot of memory. For example,
 let's find the day on which the route 22 bus had the greatest

Exercises/ex3_1.md

@@ -8,7 +8,7 @@
 
 *Files Modified:* `stock.py`
 
-In link:ex1_5.html[Exercise 1.5], you defined a simple class
+In [Exercise 1.5](ex1_5.md), you defined a simple class
 `Stock` for representing a holding of stock.  In this exercise,
 we're simply going to add a few features to that class as well as
 write some utility functions.
@@ -49,7 +49,7 @@ reads a file of portfolio data into a list of `Stock` objects. Here's how it sho
 ```
 
 You already wrote a similar function as part of
-link:ex2_3.html[Exercise 2.3].  Design discussion: Should
+[Exercise 2.3](ex2_3.md).  Design discussion: Should
 `read_portfolio()` be a separate function or part of the class
 definition?
 

Exercises/ex3_2.md

@@ -66,7 +66,7 @@ price 490.1
 
 ## (c) Table Output
 
-In link:ex3_1.html[Exercise 3.1], you wrote a function `print_portfolio()`
+In [Exercise 3.1](ex3_1.md), you wrote a function `print_portfolio()`
 that made a nicely formatted table.   That function was custom tailored
 to a list of `Stock` objects.  However, it can be completely generalized
 to work with any list of objects using the technique in part (b).

Exercises/ex3_5.md

@@ -13,7 +13,7 @@ CSV, and HTML.
 
 One major use of classes in Python is in writing code that be
 extended/adapted in various ways.  To illustrate, in
-link:ex3_2.html[Exercise 3.2] you created a function `print_table()`
+[Exercise 3.2](ex3_2.md) you created a function `print_table()`
 that made tables.  You used this to make output from the `portfolio`
 list. For example:
 

Exercises/ex3_6.md

@@ -98,7 +98,7 @@ Make this change and try comparing two objects again.
 
 ## (c) A Context Manager
 
-In link:ex3_5.html[Exercise 3.5], you made it possible for users to make
+In [Exercise 3.5](ex3_5.md), you made it possible for users to make
 nicely formatted tables.  For example:
 
 ```python

Exercises/ex3_7.md

@@ -9,7 +9,7 @@
 
 *Files Modified:* `tableformat.py`
 
-In link:ex3_5.html[Exercise 3.5], we modified the `tableformat.py` file to have a `TableFormatter`
+In [Exercise 3.5](ex3_5.md), we modified the `tableformat.py` file to have a `TableFormatter`
 class and to use various subclasses for different output formats.  In this exercise, we extend that
 code a bit more.
 

Exercises/ex3_8.md

@@ -10,7 +10,7 @@
 
 ## (a) The Trouble with Column Formatting
 
-If you go all the way back to link:ex3_1.txt[Exercise 3.1], you 
+If you go all the way back to [Exercise 3.1](ex3_1.md), you 
 wrote a function `print_portfolio()` that produced a table like this:
 
 ```python
@@ -204,7 +204,7 @@ different ways.
 Using mixins can be a useful tool for framework builders for reducing 
 the amount of code that needs to be written.  However, forcing users
 to remember how to properly compose classes and use multiple inheritance can
-fry their brains.  In link:ex3_5.html[Exercise 3.5], you wrote a 
+fry their brains.  In [Exercise 3.5](ex3_5.md), you wrote a 
 function `create_formatter()` that made it easier to create a custom
 formatter.  Take that function and extend it to understand a few optional
 arguments related to the mixin classes. For example:

Exercises/ex4_2.md

@@ -123,7 +123,7 @@ the end of the MRO since it is the parent to all of the classes being composed t
 
 ## (b) Build a Value Checker
 
-In link:ex3_4.html[Exercise 3.4], you added some properties to the `Stock` class that
+In [Exercise 3.4](ex3_4.md), you added some properties to the `Stock` class that
 checked attributes for different types and values (e.g., shares had to be a positive
 integer).  Let's play with that idea a bit.  Start by creating a file `validate.py` and
 defining the following base class:

Exercises/ex6_1.md

@@ -16,7 +16,7 @@ sane way.   Before doing anything, copy your work in `stock.py` to a new file
 `orig_stock.py`.  
 
 We're going to recreate the `Stock` class from scratch using some new techniques.
-Make sure you have your unit tests from link:ex5_4.html[Exercise 5.4] handy. You'll want those.
+Make sure you have your unit tests from [Exercise 5.4](ex5_4.md) handy. You'll want those.
 
 If you define a function, you probably already know that it can be
 called using a mix of positional or keyword arguments.  For example: