My talk during ID-Python Jogja November 2016 at Sebangsa about the Zen of Python in real world use case based on my personal experience

1. PRACTICAL ZEN
OF PYTHON
@FEMMERLING - ID-PYTHON JOGJA NOV
2016

2. PRACTICAL ZEN OF PYTHON
A BIT ABOUT ME
▸Fauzan Erich Emmerling
▸Married, 3 kids all of which will grow up learning python :)
▸Using python since 2010 and still learning more
▸Lives in Jogja after 14 years struggling with massive traffic jam in
Jakarta
▸VP of Engineering at Prism, yes we’re hiring!
▸@femmerling on twitter @fauzan on python-id slack
fauzan@python.or.id fauzan@prismapp.io

3. THE ZEN OF
PYTHON
IS ALL ABOUT
ENGINEERING

4. “IN REALITY, PROGRAMMING
LANGUAGES ARE HOW
PROGRAMMERS EXPRESS AND
COMMUNICATE IDEAS — AND THE
AUDIENCE FOR THOSE IDEAS IS
OTHER PROGRAMMERS, NOT
COMPUTERS.”
Guido van Rossum
PRACTICAL ZEN OF PYTHON

5. PRACTICAL ZEN OF PYTHON
THE ZEN OF PYTHON>>> import this
The Zen of Python, by Tim Peters
Beautiful is better than ugly.
Explicit is better than implicit.
Simple is better than complex.
Complex is better than complicated.
Flat is better than nested.
Sparse is better than dense.
Readability counts.
Special cases aren't special enough to break the rules.
Although practicality beats purity.
Errors should never pass silently.
Unless explicitly silenced.
In the face of ambiguity, refuse the temptation to guess.
There should be one-- and preferably only one --obvious way to do it.
Although that way may not be obvious at first unless you're Dutch.
Now is better than never.
Although never is often better than *right* now.
If the implementation is hard to explain, it's a bad idea.
If the implementation is easy to explain, it may be a good idea.
Namespaces are one honking great idea -- let's do more of those!

6. PRACTICAL ZEN OF PYTHON
BEAUTIFUL IS BETTER THAN UGLY
▸Write codes that is nice to read and understand
▸Simple expression syntax
▸Be consistent
▸I know this is hard: pick meaningful names

7. PRACTICAL ZEN OF PYTHON
BEAUTIFUL IS BETTER THAN UGLY -
CODE EXAMPLE

8. PRACTICAL ZEN OF PYTHON
EXPLICIT IS BETTER THAN IMPLICIT
▸State what you mean, explicitly
▸The for loop is very explicit
▸Remember, the goal is to exchange ideas
▸Leverage the Booleans
▸Be explicit and revealing when it comes to variable or
function naming

9. PRACTICAL ZEN OF PYTHON
EXPLICIT IS BETTER THAN IMPLICIT -
CODE EXAMPLE

10. PRACTICAL ZEN OF PYTHON
SIMPLE IS BETTER THAN COMPLEX
▸Always aim for simplicity
▸Do not use OOP when it’s not needed
▸Aim for lesser lines of code
▸Less code == less confusion == more clarity

11. PRACTICAL ZEN OF PYTHON
SIMPLE IS BETTER THAN COMPLEX -
CODE EXAMPLE

12. PRACTICAL ZEN OF PYTHON
COMPLEX IS BETTER THAN
COMPLICATED
▸When simple is not possible, be complex
▸Complicated can lead to misunderstanding
▸Complex code increases comprehension

13. PRACTICAL ZEN OF PYTHON
COMPLEX IS BETTER THAN
COMPLICATED - CODE EXAMPLE

14. PRACTICAL ZEN OF PYTHON
FLAT IS BETTER THAN NESTED
‣ Use modules instead of nested if
‣ Use stdlib, it’s batteries included

15. PRACTICAL ZEN OF PYTHON
FLAT IS BETTER THAN NESTED - CODE
EXAMPLE

16. PRACTICAL ZEN OF PYTHON
SPARSE IS BETTER THAN DENSE
‣ Be loosely coupled
‣ Do one thing and do it well - - the UNIX philosophy

17. PRACTICAL ZEN OF PYTHON
SPARSE IS BETTER THAN DENSE -
CODE EXAMPLE

18. PRACTICAL ZEN OF PYTHON
READABLITY COUNTS
‣ Use consistent whitespace (space VS tabs)
‣ Use inline documentation
‣ Code for humans

19. PRACTICAL ZEN OF PYTHON
READABILITY COUNTS - CODE EXAMPLE

20. PRACTICAL ZEN OF PYTHON
SPECIAL CASE ARE NOT SPECIAL
ENOUGH TO BREAK THE RULES
‣ Everything is an object
‣ The scope rule

21. PRACTICAL ZEN OF PYTHON
ALTHOUGH PRACTICALITY BEATS PURITY,
ERRORS SHOULD NEVER PASS SILENTLY,
UNLESS EXPLICITLY SILENCED
‣ Python has a multi-model approach. It is:
‣ Procedural
‣ OOP
‣ Functional
‣ Errors should be handled using exceptions
‣ Graceful handling should be done via try - except

22. PRACTICAL ZEN OF PYTHON
IN THE FACE OF AMBIGUITY, REFUSE
THE TEMPTATION TO GUESS
‣ Type handling is sometimes surprising
‣ You can’t add 2 different types
‣ You can multiply them

23. PRACTICAL ZEN OF PYTHON
THERE SHOULD BE ONE - - AND PREFERABLY ONLY
ONE - - OBVIOUS WAY TO DO IT.
ALTHOUGH THAT WAY MAY NOT BE OBVIOUS AT
FIRST UNLESS YOU’RE DUTCH
‣ Be DRY
‣ Don’t be redundant
‣ Better learning curve
‣ Easier for distributed teams
‣ When confused, remember that the BDFL is Dutch :)

24. PRACTICAL ZEN OF PYTHON
NOW IS BETTER THAN NEVER,
ALTHOUGH NEVER IS OFTEN BETTER THAN *RIGHT*
NOW‣ Ports to other language, i.e: Jython, IronPython
‣ The python 2 VS 3 battle
‣ stdlib has stricter requirements

25. PRACTICAL ZEN OF PYTHON
IF THE IMPLEMENTATION IS HARD TO EXPLAIN, IT’S
A BAD IDEA
IF THE IMPLEMENTATION IS EASY TO EXPLAIN, IT
MAY BE A GOOD IDEA
‣ Back to Guido’s quote on slide 3
‣ Explain ideas through your codes
‣ Simplicity is the ultimate sophistication

26. PRACTICAL ZEN OF PYTHON
NAMESPACES ARE ONE HONKING GREAT
IDEA - - LET’S DO MORE OF THOSE
‣ Closures for better module separation
‣ Fun to use

27. SO WHAT’S
NEXT?

28. PRACTICAL ZEN OF PYTHON
KEY TAKEAWAYS
▸Make your code understandable
▸Simplicity is the ultimate sophistication
▸When in doubt, “import this”
▸Do it today

29. QUESTION
S?

30. THANKS!!!