Python for Java developers

Transcript

1. Can I haz ur pythons? Rafael Medina García @rmed_dev Fco. Javier Honduvilla Coto @javierhonduco
2. Where is python?
3. Examples for the Java weenies
4. Simple TCP Socket: Java
5. Simple TCP Socket: Python
6. Reading a file: Java
7. Reading a file: Python
8. Hashtable: Java
9. “Hashtable”: Python
10. Why python rocks? • Function parameters • GC ◦ Reference counting • Decorators • Types (WTF) • List-Stack-Queue-[...] • PyPI
11. Concurrency is not parallelism • Concurrency ◦ GIL: Global Interpreter Lock (</3) i. threads vs processes • celery ii. tasks iii. groups iv. pipes • cpython, pypy
12. Celery • Async framework task Queue + Tasks = fun
13. Cpython and moar • cpython ◦ Guido’s Python Interpreter • pypy ◦ “an implementation of the Python programming language written in Python itself”
14. Web frameworks + wsgi • Django • Flask • ∞
15. Scientific packages • ipython + notebook • cython • numba...
16. Our fav libs • requests (http for humans) • SQLAlchemy (database toolkit)
17. SQLAlchemy I
18. SQLAlchemy II
19. Is (c)python slow? • Overhead • Cache misses • Complex data structures • Any variable can change its type • (dynamic)
21. Bibliography • https://jakevdp.github.io/blog/2014/05/09/why-python-is- slow/ • http://docs.python-requests.org/en/latest/ • https://bitbucket.org/zzzeek/sqlalchemy • http://wsgi.readthedocs.org/en/latest/ • http://www.dabeaz.com/python/UnderstandingGIL.pdf • https://docs.python.org/2/library/gc.html • https://pypi.python.org/pypi • http://pypy.org/ • http://www.scipy.org/