Added links. Renumber exercises

Notes/02_Working_with_data/03_Formatting.md

@@ -101,7 +101,7 @@ b'Dave has 37 messages'
 
 ## Exercises
 
-In the previous exercise, you wrote a program called `report.py` that computed the gain/loss of a
+In Exercise 2.7, you wrote a program called `report.py` that computed the gain/loss of a
 stock portfolio.  In this exercise, you're going to modify it to produce a table like this:
 
 ```code
@@ -116,12 +116,15 @@ stock portfolio.  In this exercise, you're going to modify it to produce a table
            IBM        100     106.28      35.84
 ```
 
-In this report, "Price" is the current share price of the stock and "Change" is the change in the share price from the initial purchase price.
+In this report, "Price" is the current share price of the stock and
+"Change" is the change in the share price from the initial purchase
+price.
 
-### (a) How to format numbers
+### Exercise 2.8: How to format numbers
 
-A common problem with printing numbers is specifying the number of decimal places. One way to fix this is to use f-strings. Try
-these examples:
+A common problem with printing numbers is specifying the number of
+decimal places. One way to fix this is to use f-strings. Try these
+examples:
 
 ```python
 >>> value = 42863.1
@@ -150,7 +153,8 @@ is also sometimes performed using the `%` operator of strings.
 >>>
 ```
 
-Documentation on various codes used with `%` can be found [here](https://docs.python.org/3/library/stdtypes.html#printf-style-string-formatting).
+Documentation on various codes used with `%` can be found
+[here](https://docs.python.org/3/library/stdtypes.html#printf-style-string-formatting).
 
 Although it’s commonly used with `print`, string formatting is not tied to printing.
 If you want to save a formatted string. Just assign it to a variable.
@@ -162,14 +166,15 @@ If you want to save a formatted string. Just assign it to a variable.
 >>>
 ```
 
-### (b) Collecting Data
+### Exercise 2.9: Collecting Data
 
 In order to generate the above report, you’ll first want to collect
 all of the data shown in the table.  Write a function `make_report()`
 that takes a list of stocks and dictionary of prices as input and
 returns a list of tuples containing the rows of the above table.
 
-Add this function to your `report.py` file. Here’s how it should work if you try it interactively:
+Add this function to your `report.py` file. Here’s how it should work
+if you try it interactively:
 
 ```pycon
 >>> portfolio = read_portfolio('Data/portfolio.csv')
@@ -187,9 +192,10 @@ Add this function to your `report.py` file. Here’s how it should work if you t
 >>>
 ```
 
-### (c) Printing a formatted table
+### Exercise 2.10: Printing a formatted table
 
-Redo the above for-loop, but change the print statement to format the tuples.
+Redo the for-loop in Exercise 2.9, but change the print statement to
+format the tuples.
 
 ```pycon
 >>> for r in report:
@@ -220,7 +226,7 @@ You can also expand the values and use f-strings. For example:
 Take the above statements and add them to your `report.py` program.
 Have your program take the output of the `make_report()` function and print a nicely formatted table as shown.
 
-### (d) Adding some headers
+### Exercise 2.11: Adding some headers
 
 Suppose you had a tuple of header names like this:
 
@@ -257,7 +263,7 @@ When you’re done, your program should produce the table shown at the top of th
            IBM        100     106.28      35.84
 ```
 
-### (e) Formatting Challenge
+### Exercise 2.12: Formatting Challenge
 
 How would you modify your code so that the price includes the currency symbol ($) and the output looks like this:
 
@@ -273,4 +279,4 @@ How would you modify your code so that the price includes the currency symbol ($
            IBM        100    $106.28      35.84
 ```
 
-[Next](04_Sequences)
+[Contents](../Contents) \| [Previous (2.2 Containers)](02_Containers) \| [Next (2.4 Sequences)](04_Sequences)