The document discusses the transition from Python 2 to Python 3, emphasizing the benefits and features of Python 3 for developers. It provides insights on discussing the change with management, the readiness of libraries for Python 3, and encourages the adoption of Python 3 for new projects and side projects. Additionally, the document highlights the significance of learning new syntax and capabilities of Python 3 for maintaining a competitive edge in software development.

1. How to Stop Worrying and Start a Project
with Python 3
Viacheslav Kakovskyi
Austin Python Meetup 2017

2. Me!
Backend Software Technical Lead
Python 2 and Twisted → Python 3 and asyncio
Ukraine → Austin, Texas
Share knowledge at Python events
● PyCon Ukraine 2016
● PyCon Poland 2016
● KyivPy 2015, WebCamp Ukraine 2016
● Austin Python Meetup 2017
2
@kakovskyi

3. 3
3 months back from today...
https://www.slideshare.net/mariczhuck/austin-python-meetup-2017-whats-new-in-pythons-35-and-36

4. Agenda
1. The story about my journey from 2 to 3
2. Should I use Python 3, not 2?
3. Discover the benefits with your team
4. How to discuss switching to Python 3 with your
manager
5. Summary
4

5. Who uses
Python 3
in production?
5

6. The story about my journey
6
# python2
@defer.inlineCallbacks
# python2, small projects
@app.route('')

7. The story about my journey
7
# python2, big project
d = defer.Deferred()
d.addCallback(foo)
d.addErrback(bar)
# python3, non-commercial project
async / await

8. The story about my journey
8
# python3, big project

9. Should I use
Python 3, not 2?
9

10. Reasons to use Python 3 for a developer
10

11. Reasons to use Python 3 for a developer
11
New syntax features make our life easier
● PEP 448, additional unpacking generalizations
● PEP 465, a new matrix multiplication operator `a @ b`
● PEP 492, coroutines with async and await syntax
● PEP 498, formatted string literals
● PEP 515, underscores in numeric literals
● PEP 525, asynchronous generators
● PEP 526, syntax for variable annotations
● PEP 530, asynchronous comprehensions
● and others

12. PyCharm: in late 2017 py3.users > py2.users
12

13. Does ... work with Python 3?
13
95% of most popular
PyPI libraries support
Python 3
http://py3readiness.org/

14. New Python libraries will be Python 3 only
14
Libs tagged on PyPI
● Python 3: 55.5%
○ 75669 releases
● Python 2: 44.5%
○ 60732 releases

15. Libs releases tagged on PyPI
15
Python 3 (75669)
● 3 (22701)
● 3.0 (733)
● 3.1 (1161)
● 3.2 (4902)
● 3.3 (13462)
● 3.4 (17117)
● 3.5 (12793)
● 3.6 (2800)
Python 2 (60732)
● 2 (16725)
● 2.3 (87)
● 2.4 (440)
● 2.5 (1333)
● 2.6 (11142)
● 2.7 (31005)

16. Py2 EOL in 3 yrs
16
https://pythonclock.org/

17. 17
Is Python 3 a thing
for your team?

18. Rewriting
Python 2 service
from scratch
with Python 3
18

19. 19
(STARE)
ARE YOU SURE?

20. Extending functionality with new services
20

21. Creating
async
services
easily
21

22. Welcome to the async World!
22
○ aiohttp_admin
○ aiomcache
○ aiocouchdb
○ aiomeasures
○ aiobotocore
○ aiozmq
○ aioodbc
○ aiokafka
○ aioes
○ your async library here
○ aiohttp
○ aiopg
○ aiomysql
○ aioredis
○ aiokafka

23. Better developers experience
23
● async /await
● typing module and type hinting
● tracemalloc module
● asynctest library
● hypothesis library
● behave library

24. Discuss
switching to
Python 3 with
your manager
24

25. 0. Make side
project with
Python 3
25

26. 1. Find small
isolated part
of your
project
26

27. 2. Implement
that with
Python 3 using
the new things
27

28. 28
3. Tell the manager that the
part will still be working in
2020... not as the rest of
codebase

29. (previous slide was a joke)
29

30. Experience of my team:
Dev speed is pretty good
after the first month
30

31. Summary
● The future is already here
● Learn new Python 3 features - they are great
● Make side projects and prototypes to gain experience
● New learners - invest your time only in Python 3
● Start new projects only with Python 3
31

32. 32

33. 33
@kakovskyi
viach.kakovskyi@gmail.com
Questions?