The document summarizes a coding dojo session led by Peter Kofler on parsing bank account numbers from an optical character recognition (OCR) file. The session followed a structured format including introductions, coding periods with retrospectives, and a closing circle. Participants were assigned to write a program to take an OCR file with account numbers represented as pipes and underscores and parse it into actual numbers, with considerations for readability, matching digits, and flexibility. The goal was to focus on doing the assignment perfectly rather than just getting it done.

1. Coding Dojo:
Bank OCR
Austrian Institute of Technology
September 2014
Peter Kofler, ‘Code Cop’
@codecopkofler
www.code-cop.org
Copyright Peter Kofler, licensed under CC-BY.

2. PETER KOFLER, CODE-COP.ORG FANATIC ABOUT CODE QUALITY
Peter Kofler
• Ph.D. (Appl. Math.)
• Professional Software
Developer for 15 years
• “fanatic about code quality”
• I help development teams

3. Coding Dojo?
Expectations?

4. PETER KOFLER, CODE-COP.ORG FANATIC ABOUT CODE QUALITY
Coding Dojo Mindset
● Safe place outside
work
● We are here to learn
● Need to slow down
● Focus on doing it right
● Collaborative Game

5. PETER KOFLER, CODE-COP.ORG FANATIC ABOUT CODE QUALITY
Dojo Structure
● Introduction 15'
● Coding 45'
● Interim (Retrospective) 15'
● Break 10'
● Coding 45'
● Retrospective 15'

6. PETER KOFLER, CODE-COP.ORG FANATIC ABOUT CODE QUALITY
Assignment

7. PETER KOFLER, CODE-COP.ORG FANATIC ABOUT CODE QUALITY
Bank OCR
● You work for a bank, which has a machine to assist in
reading letters. The machine scans the paper
documents, and produces a file with a number of
entries which each look like this:
····_··_·····_··_··_··_··_·
··|·_|·_||_||_·|_···||_||_|
··||_··_|··|·_||_|··||_|·_|
···························
● Each entry is 4 lines long, each line has 27 characters.
The first 3 lines contain an account number written
using pipes and underscores, and the fourth line
is blank. Each account number should have 9 digits,
all of which should be in the range 1-9.

8. PETER KOFLER, CODE-COP.ORG FANATIC ABOUT CODE QUALITY
Bank OCR
● Write a program that can take this file
and parse it into actual account
numbers.
● Find a pair.
● Choose a programming language.
● Set up the environment.
● Start with creating a test.

9. Don't Focus on
Getting it Done.
F0cus on Doing
It Perfectly.

10. → Practice

11. PETER KOFLER, CODE-COP.ORG FANATIC ABOUT CODE QUALITY
Bank OCR considerations
● Which algorithm did you chose?
● How readable are your test cases? (Can you
look at them and easily see which digits are being parsed?)
● How do you match digits? (Are you using low
level Ifs or high level patterns to match?)
● Functional or imperative? (Do you use
iteration or recursion?)
● What if the input changes? (What about the
style of digits, number of digits, ...)

12. → Practice

13. PETER KOFLER, CODE-COP.ORG FANATIC ABOUT CODE QUALITY
Closing Circle
● What did you learn today?
● What surprised you today?
● What will you do
differently in the
future?

14. PETER KOFLER, CODE-COP.ORG FANATIC ABOUT CODE QUALITY
Peter Kofler
@codecopkofler
www.code-cop.org

15. PETER KOFLER, CODE-COP.ORG FANATIC ABOUT CODE QUALITY
CC Images
● Bank https://www.flickr.com/photos/bigmacsc99/4325336251
● Dojo
http://www.flickr.com/photos/49715404@N00/3267627038/
● Todos
http://www.flickr.com/photos/kylesteeddesign/3724074594/
● Wants you http://www.flickr.com/photos/shutter/105497713/