Added links

Notes/03_Program_organization/01_Script.md

@@ -1,4 +1,4 @@
-# 3.1 Python Scripting
+# 3.1 Scripting
 
 In this part we look more closely at the practice of writing Python
 scripts.
@@ -233,7 +233,7 @@ for row in report:
 
 In this exercise, we’re going take this program and organize it a little more strongly around the use of functions.
 
-### (a) Structuring a program as a collection of functions
+### Exercise 3.1: Structuring a program as a collection of functions
 
 Modify your `report.py` program so that all major operations,
 including calculations and output, are carried out by a collection of
@@ -242,7 +242,7 @@ functions. Specifically:
 * Create a function `print_report(report)` that prints out the report.
 * Change the last part of the program so that it is nothing more than a series of function calls and no other computation.
 
-### (b) Creating a function for program execution
+### Exercise 3.2: Creating a function for program execution
 
 Take the last part of your program and package it into a single function `portfolio_report(portfolio_filename, prices_filename)`.
 Have the function work so that the following function call creates the report as before:
@@ -272,4 +272,4 @@ For example, try these statements interactively after running your program:
 >>>
 ```
 
-[Next](02_More_functions)
+[Contents](../Contents) \| [Previous (2.7 Object Model)](../02_Working_with_data/07_Objects) \| [Next (3.2 More on Functions)](02_More_functions)

Notes/03_Program_organization/02_More_functions.md

@@ -253,7 +253,7 @@ our goal.
 
 Start this exercise by creating a new file called `fileparse.py`. This is where we will be doing our work.
 
-### (a) Reading CSV Files
+### Exercise 3.3: Reading CSV Files
 
 To start, let’s just focus on the problem of reading a CSV file into a
 list of dictionaries.  In the file `fileparse.py`, define a simple
@@ -300,7 +300,7 @@ Hint: `python3 -i fileparse.py`.
 This is great except that you can’t do any kind of useful calculation with the data because everything is represented as a string.
 We’ll fix this shortly, but let’s keep building on it.
 
-### (b) Building a Column Selector
+### Exercise 3.4: Building a Column Selector
 
 In many cases, you’re only interested in selected columns from a CSV file, not all of the data.
 Modify the `parse_csv()` function so that it optionally allows user-specified columns to be picked out as follows:
@@ -318,7 +318,7 @@ Modify the `parse_csv()` function so that it optionally allows user-specified co
 >>>
 ```
 
-An example of a column selector was given in Section 2.5.
+An example of a column selector was given in [Exercise 2.23](../02_Working_with_data/06_List_comprehension).
 However, here’s one way to do it:
 
 ```python
@@ -394,7 +394,7 @@ When you read a row of data from the file, the indices are used to filter it:
 >>>
 ```
 
-### (c) Performing Type Conversion
+### Exercise 3.5: Performing Type Conversion
 
 Modify the `parse_csv()` function so that it optionally allows type-conversions to be applied to the returned data.
 For example:
@@ -410,7 +410,7 @@ For example:
 >>>
 ```
 
-You already explored this in Exercise 2.7.  You'll need to insert the
+You already explored this in [Exercise 2.24](../02_Working_with_data/07_Objects).  You'll need to insert the
 following fragment of code into your solution:
 
 ```python
@@ -420,7 +420,7 @@ if types:
 ...
 ```
 
-### (d) Working with Headers
+### Exercise 3.6: Working with Headers
 
 Some CSV files don’t include any header information.
 For example, the file `prices.csv` looks like this:
@@ -448,7 +448,7 @@ line of data isn’t interpreted as a header line.  Also, you’ll need to
 make sure you don’t create dictionaries as there are no longer any
 column names to use for keys.
 
-### (e) Picking a different column delimitier
+### Exercise 3.7: Picking a different column delimitier
 
 Although CSV files are pretty common, it’s also possible that you could encounter a file that uses a different column separator such as a tab or space.
 For example, the file `Data/portfolio.dat` looks like this:
@@ -486,6 +486,4 @@ You can use it to parse arbitrary CSV files, select out columns of
 interest, perform type conversions, without having to worry too much
 about the inner workings of files or the `csv` module.
 
-Nice!
-
-[Next](03_Error_checking)
+[Contents](../Contents) \| [Previous (3.1 Scripting)](01_Script) \| [Next (3.3 Error Checking)](03_Error_checking)

Notes/03_Program_organization/03_Error_checking.md

@@ -301,7 +301,7 @@ resources are released. `with` only works with certain objects.
 
 ## Exercises
 
-### (a) Raising exceptions
+### Exercise 3.8: Raising exceptions
 
 The `parse_csv()` function you wrote in the last section allows
 user-specified columns to be selected, but that only works if the
@@ -336,7 +336,7 @@ headers, but simultaneously specifying that there are no headers).
 
 This indicates a programming error on the part of the calling code.
 
-### (b) Catching exceptions
+### Exercise 3.9: Catching exceptions
 
 The `parse_csv()` function you wrote is used to process the entire
 contents of a file.  However, in the real-world, it’s possible that
@@ -373,7 +373,7 @@ Row 7: Reason invalid literal for int() with base 10: ''
 >>>
 ```
 
-### (c) Silencing Errors
+### Exercise 3.10: Silencing Errors
 
 Modify the `parse_csv()` function so that parsing error messages can be silenced if explicitly desired by the user.
 For example:
@@ -390,4 +390,4 @@ most programs.  As a general rule, you shouldn’t silently ignore
 errors.  Instead, it’s better to report problems and to give the user
 an option to the silence the error message if they choose to do so.
 
-[Next](04_Modules)
+[Contents](../Contents) \| [Previous (3.2 More on Functions)](02_More_functions) \| [Next (3.4 Modules)](04_Modules)

Notes/03_Program_organization/04_Modules.md

@@ -197,7 +197,7 @@ make sure you are running Python in a proper environment.  Modules
 are usually when programmers encounter problems with the current working
 directory or with Python's path settings.
 
-### (a) Module imports
+### Exercise 3.11: Module imports
 
 In section 3, we created a general purpose function `parse_csv()` for parsing the contents of CSV datafiles.
 
@@ -268,7 +268,7 @@ Try importing a function so that you don’t need to include the module name:
 >>>
 ```
 
-### (b) Using your library module
+### Exercise 3.12: Using your library module
 
 In section 2, you wrote a program `report.py` that produced a stock report like this:
 
@@ -292,7 +292,7 @@ and `read_prices()` functions to use the `parse_csv()` function.
 Use the interactive example at the start of this exercise as a guide.
 Afterwards, you should get exactly the same output as before.
 
-### (c) Using more library imports
+### Exercise 3.14: Using more library imports
 
 In section 1, you wrote a program `pcost.py` that read a portfolio and computed its cost.
 
@@ -314,4 +314,4 @@ also contains `read_portfolio()` and `read_prices()` functions.  And
 finally, `pcost.py` which computes the portfolio cost, but makes use
 of the code written for the `report.py` program.
 
-[Next](05_Main_module)
+[Contents](../Contents) \| [Previous (3.3 Error Checking)](03_Error_checking) \| [Next (3.5 Main Module)](05_Main_module)

Notes/03_Program_organization/05_Main_module.md

@@ -249,7 +249,7 @@ if __name__ == '__main__':
 
 ## Exercises
 
-### (a) `main()` functions
+### Exercise 3.15: `main()` functions
 
 In the file `report.py` add a `main()` function that accepts a list of command line options and produces the same output as before.
 You should be able to run it interatively like this:
@@ -278,7 +278,7 @@ Total cost: 44671.15
 >>>
 ```
 
-### (b) Making Scripts
+### Exercise 3.16: Making Scripts
 
 Modify the `report.py` and `pcost.py` programs so that they can execute as a script on the command line:
 
@@ -297,3 +297,5 @@ bash $ python3 report.py Data/portfolio.csv Data/prices.csv
 bash $ python3 pcost.py Data/portfolio.csv
 Total cost: 44671.15
 ```
+
+[Contents](../Contents) \| [Previous (3.4 Modules)](04_Modules) \| [Next (3.6 Design Discussion)](06_Design_discussion)

Notes/03_Program_organization/06_Design_discussion.md

@@ -85,7 +85,7 @@ Don't restrict your options.  With great flexibility comes great power.
 
 ## Exercise
 
-### (a)From filenames to file-like objects
+### Exercise 3.17: From filenames to file-like objects
 
 In this section, you worked on a file `fileparse.py` that contained a 
 function `parse_csv()`.  The function worked like this:
@@ -123,10 +123,12 @@ In this new code, what happens if you pass a filename as before?
 With flexibility comes power and with power comes responsibility.  Sometimes you'll
 need to be careful.
 
-### (b) Fixing existing functions
+### Exercise 3.18: Fixing existing functions
 
 Fix the `read_portfolio()` and `read_prices()` functions in the
 `report.py` file so that they work with the modified version of
 `parse_csv()`.  This should only involve a minor modification.
 Afterwards, your `report.py` and `pcost.py` programs should work
 the same way they always did.
+
+[Contents](../Contents) \| [Previous (3.5 Main module)](05_Main_module) \| [Next (4 Classes)](../04_Classes_objects/00_Overview)