Mittwoch, 24. Oktober 2012

Learn Python and SQLAlchemy in Antwerp, Belgium

So far most of our open courses are in Leipzig, Germany. After an open training right after EuroPython in Florence in July and one after PyCon PL in Poland in September, we now also offer Python training in Antwerp, Belgium. This is in collaboration with Conceptive Engineering.

Python for Programmers - November 12 - 14, 2012
This is an introduction to the Python Programming languages for participants with some programming background in another language. The three days provide a hands-on training covering all basic language features. After the course participants can write their own Python programs. Stress is on pythonic solutions, i.e. taking advantage of Python's strengths while writing elegant and efficient code.
See the course page for more information.

SQLAlchemy Training - November 15, 2012
SQLAlchemy is THE the library to use in the Python world when interacting with databases. It provides a full suite of well known enterprise-level persistence patterns, designed for efficient and high-performing database access, adapted into a simple and Pythonic domain language.
This practical course will make sure you understand the concepts behind SQLAlchemy. We will focus on practical patterns of SQLAlchemy usage and see how its use can grow from very simple to more advanced.
See the course page for more information.

Camelot Training - November 16,  2012
Camelot is a framework for developing desktop database applications at warp speed. It is to desktop applications what Django is to web applications. Some see it as a replacement for MS Access, but its tight integration with SQLAlchemy enables a vast amount of more advanced features and possibilities.
See the course page for more information.

Freitag, 7. September 2012

Advanced Python in Poland, Django in Germany, or SQLAlchemy in Belgium?

If you are interested in Python courses, please read on.

The table below shows our next courses. The very next one is just a bit more than a week ahead.

Our Advanced Python course at EuroPython in Florence in July was a great succes. Therefore, we offer this course again just subsequent to PyCon PL Advanced Python at PyCon PL. There is a big discount for PyCon PL attendees. Actually, the price for the conference and the course together is lower than for the course alone.

How about five days of intensive Django submersion? Upon request now in English (Introduction to DjangoAdvanced Django).

Would you like to get up to speed with SQLAlchemy? Pick your course location: Germany or Belgium? (SQLAlchemy).

There is more (see table below):

  • Python Introduction
  • Python for Scientists and Engineers
  • High Performance Python 

All courses are offered in English; some additionally in German.

Location Date Course Language
Mąchocice Poland PyCon PL September 17 - 18, 2012 Advanced Python at PyCon PL English
Leipzig October 15 - 17, 2012 Introduction to Django English
Leipzig October 18 - 20, 2012 Advanced Django English
Leipzig October 27, 2012 SQLAlchemy English
Leipzig October 28, 2012 Camelot English
Antwerp Belgium November 12 - 14, 2012 Python for Programmers English
Antwerp Belgium November 15, 2012 SQLAlchemy English
Antwerp Belgium November 16, 2012 Camelot English
Leipzig December 10 - 12, 2012 Python für Programmierer German
Leipzig December 13 - 15, 2013 Python für Wissenschaftler und Ingenieure German
Leipzig January 25 - 27, 2013 Advanced Python Course English
Leipzig January 28 - 30, 2013 High-Performance Computation with Python English
Leipzig January 28, 2013 Optimizing Python Programs English
Leipzig January 29, 2013 Python Extensions with Other Languages English
Leipzig January 30, 2013 Fast Code with the Cython Compiler English
Leipzig January 31 - February 1, 2013 High Performance XML with Python English
Chicago, USA March 4 - 8, 2013 Python for Scientists and Engineers (USA) English
Leipzig April 15 - 17, 2013 Python für Programmierer German
Leipzig April 18 - 20, 2013 Python für Wissenschaftler und Ingenieure German
Leipzig June 10 - 12, 2013 Python for Scientists and Engineers English
Leipzig June 13, 2013 Fast Code with the Cython Compiler English
Leipzig June 14, 2013 Fast NumPy Processing with Cython English

Donnerstag, 6. September 2012

EuroSciPy 2012 in Brussels - A Special Conference

A Great Conference
At the End of August 2012 the EuroSciPy conference took place in Brussels, Belgium. This was edition number 5 after two conferences in Leipzig, Germany in 2008 and 2009 and the other two in Paris, France in 2010 and 2011. Next year, this event will be again in Brussels.

The whole conference took four days: two days of tutorials followed by two days of talks.1 This is quite unique for a conference where usually the talk part is predominant. In fact, there was roughly twice as much tutorial time as talk time because two tutorial sessions proceeded in parallel, an introductory track and an advanced track. The tutorials were great. You get lots of hands-on training in a very short period of time.

Tutorial Day 1 (Advanced only)
As the first thing on Thursday, I gave a tutorial about combining Cython and NumPy and going parallel with OpenMP. This is essentially an abstract of a one-day course on this subject compressed into one hour and fifteen minutes. Admittedly, it is not the simplest topic, especially if you are new to Cython and, even more so, to NumPy. But after all, it was in the advanced tack and the 100+ people in the room must have got something out of it. At least the feedback as good.

The rest of the two tutorial days I could enjoy the advanced tutorials track. In the second tutorial of the morning, Francesc Alted talked about "Numexpr, Blosc and CArray" and made clear that the bottleneck is often not the CPU but rather how fast you can get your data from memory to the CPU. Caching and memory layout are very important. All the horse power won't help if you have to wait at red lights all the time. CArray is a chunked array that allows compression. It can save a lot of memory if the array is large and rather regular, i.e. repeated numbers. Blosc for compression and Numexpr for the calculation make it really fast, even faster than contiguous NumPy arrays for some special cases. Furthermore, it also allows for disked-based arrays just in case your memory is not big enough for your data but you still want to treat it as if it would be all in memory.

In the afternoon, Ian Ozsvald gave a very nice overview how to do parallel computing in Python Parallel computing with Multiprocessing, ParallelPython and Ipython. He has a lot of experience in this field. Since his focus was on approaches for distributed computing, it was a good complement to my tutorial about shared memory computations with OpenMP.

Optimization from the SciPy perspective was the topic of the tutorial by Gaël Varoquaux Better numerics with SciPy. This was very interesting because it focussed on the science but also made clear what the SciPy package can do and what is still missing. Optimization is general enough to be appealing to many people at the conference.

Tutorial Day 2 (Advanced only)
How to make writing a GUI program simple was the topic of the tutorial Enaml is not a Markup Language by Didrik Pinte. It looks a bit like YAML but allows to create powerful GUIs for wxPython and PySide/PyQT backends. There are a lot of goodies in it that help to solve common problems like two-way communication between data and widgets with very little code, I mean markup.

Working with data, especially Big Data, in Python? Then pandas is a must. Wes McKinney showed the most prominent feature of his library in his tutorial Time Series Data Analysis with Pandas. It is impressive how easy it is to work with dates and the always so nasty missing values. Wes created a great piece of software and even wrote a book about it.

Pietro Berkes gave a good introduction to the unittest module from the standard library in his tutorial Writing robust scientific code with testing (and Python). Personally, I prefer py.test, which I think is way more powerful, simpler to use and more pythonic. He argues that it is good to use modules you don't have to install. But scientific users are used to installing third party libraries all the time and compiling C extensions is a piece of cake for them. So a pure Python package that supports a wide range of Python versions and many Python implementations should be just a pip install away.

A new perspective on packaging was presented by David Cournapeau in his tutorial Bento, a pythonic packaging system for python software. Taking into account the special requirements of scientific Python packages and incorporating existing approaches such as pypi, pip and virtualenv, this looks like a good solution for many packaging needs.

If you ever heard a presentation by David Beazley then you know that you will learn something new, get your dose of diabolic things you can do just for the fun of it and will have a great time as the talk will be as entertaining as a technical presentation can get. In his keynote on Saturday Rethinking Extension Programming he went back in the early 90s during his time as researcher and talked about his work with physics simulation programs on parallel machines. While the execution of the code was fast, the workflow for pre and post processing was horribly inefficient so that he essentially developed his own scripting language just to learn that Python had already existed. ;) As a lesson from his work on SWIG he does not think it is a good idea to wrap Python around C, C++ or FORTRAN, where Python is just the little language that makes the "real" code a bit easier to use. Just the opposite should be the case. Python is the real language and the compiled languages are just helpers. The LLVM that can be used from Python is doing just this. From Python you write native code that gets translated on the fly to machine instructions. So Python is in the lead and the compiled code follows. He gave a live coding demo which worked so well that he had a hard time to provoke a segfault just to show that you are working without the Python security net here. Overall it was a great enjoyment to attend his talk and not as diabolic as I expected.

The second keynote on Sunday by Eric Jones was about Making the Case for Python (note: I made this title up because I don't remember the exact title and cannot find it on the net). He spoke from the perspective of a leader of a software company with scientific background who "sells" Python to large institutions and companies. He enumerated common arguments against Python like it is too slow, the GIL, who uses Python, no typing etc. and gave examples how to answer to such questions. While the arguments are all too common to many long-term Python users, the experience from about 10 years Python in the cooperate world shows some new insights. As a side effect, it turned out that the audience of this conference was about 50% academia, 25 % large companies, and 25 % small companies and freelancers.

Talks Day 1
While the tutorials are about more general topics that can be useful for the daily work of a majority of the participants, the talks can become quite specialized. After all, experts from very different disciplines such as physics, biology, geoscience, engineering, finance or linguistics will talk about their latest research findings. I guess, most of people already have a Ph.D., work on their degree or plan to do so.

The first talk scikits-image: Image processing in Python by Stéfan van der Walt introduced this impressive image processing library. In short, it is not about getting rid of red eyes in party fotos but about getting information for scientific purposes out of images. Almar Klein presented an new 3D library in pure Python Visvis - an object oriented approach to visualization. If you don't need the full power of MayaVi, this might be for you. Alexandros Kanterakis showed how to apply wikipedia principles to source code writing in his talk PyPedia: A crowdsourcing python online IDE for open and reproducible science. Rickard Holmberg gave a nice example for using IronPython including the associated problems in the talks IronPython scripting in a radiation therapy treatment planning system. Fortunately, Python is not nearly as complex as a schematic of cellular processes, but you can still simulate them with Python as Johann Rohwer showed in his talk PySCeS: the Python Simulator for Cellular Systems. Brett Olivier followed up using PySCeS together with other Python tools in his talk Pathway and Cells: Systems Biology Modelling with Python. Machines can learn but they do this much differently from humans. There is a lot of powerful tools available in this area from Python as Jaques Grobler made clear in his talk New developments with Scikit-learn: machine learning in Python. Electric cars are the future and they need to be charged regularly. Simulating this with Python helps to figure out what to expect as shown by Stefan Scherfke in his talk SimPy – An Introduction and a Real-World Example with Electric Vehicles.

Talks Day 2
And now for something completely different. Steven Moran taught a 10-minute "Linguistics 101" course and showed how quantitative methods can be used in linguistics from Python in his talk A Python Library for Historical-Comparative Linguistics. Python has a strong foothold in finance as Yves Hilpisch demonstrated in Python for Finance. The audience voted the talk by Simon Ratcliffe about Python and the MeerKAT Radio Telescope as best presentation. No surprise, Python is use literally everywhere in this project. "No need to vote any more. Elections were yesterday. We just need to analyze Twitter data." This could be a yellow press headline simplify the great project Laurent Luce presented in his talk Pytolab: Twitter statistics on the 2012 French presidential election. Different topic please! How about earthquakes? What damages they can cause can be calculated, of course with Python, as Anton Gritsay explained in nhlib - a library for seismic hazard analysis. Large scale physics anyone? The talk by Mark Basham Development of the Opt-ID tool within the SDA/DAWN IDE showed impressively how Python can help to optimize the construction of a Synchrotron and just as side effect outperform existing FORTRAN code by several orders of magnitude because things are so obvious with Python. I gave the last talk showing off new Cython features to use OpenMP for GIL-less, real parallel threads in Python No GIL - Parallel Python Programming with Cython and OpenMP.

Posters are a great way to present your topic and you have time to address the questions of your audience in a one-to-one fashion. Scientists are used to posters at conferences, hence there were more posters than talks. Each poster presenter had exactly one minute for a teaser to say what his or her poster is about in front of the entire audience. This helps a lot to understand what to expect, especially at a conference with such diverse spectrum of participants as this one. There were too many poster to start mentioning them here. The best, as chosen by the audience, was the one about memory_profiler by Fabian Pedregosa. Have a look at the List of Abstracts to read about all the others. Many of them are pretty deep in their fields. For example, I do have problems to visualize eight-dimensional space. I don't know about you. ;)

Lightning Talks 
While posters are a typical science thing, lightning talks come from the programming community. I don't know any science conference with lightning talks, well, I mean except computer science. ;) But since both communities intersect here, we got them both. This three minutes of fame cover very different topics like introducing a project, asking people to help develop MayaVi, informing about startup opportunities in Chili, or advertising for PyConDE.

Many consider the hall way talk the most important of them all. You can always watch talk videos and read slides or use all the means of remote communication, but meeting people in real life is still very different. I met people who I know since the first EuroSciPy in 2008 or any other of the previous events as there were many familiar faces. I also met plenty of new people that were there for the first time.

There is no need to evangelize people about Python. They know all advantages of Python already. But it is good to see people from such diverse backgrounds using Python for things you may only have a remote idea about or none whatsoever. Still, the discussions are interesting and Python is a ground common enough to communicate and learn something new. Meeting folks from communities you typically have little contact with helps to keep your mind open.

Brussels is a nice city to conference. The atmosphere is pleasant, buildings look good, plenty of restaurants with good seafood, beer with about twice the alcohol content than what I consider average. That is how I experienced Brussels and what I heard form the other conference goers sounds pretty similar.

We had several social events exploring Brussels cuisine and beer culture. The even more relaxed atmosphere built the ground for interesting conversations and marked the beginning of the one or other the collaboration.

Organizing a conference is quite a task. I know this from my own experience being the main organizer of the first two EuroSciPy conferences in Leipzig and chairing PyConDE the second time this year. Therefore, my thanks to the organizers is even more sincere. They did a great job. Especially the two man on the ground in Brussels, Nicolas Pettiaux and Pierre de Buyl, putting in many hours of work. And they will kindly host the EuroSciPy again in 2013.

1 There were two more days with sprints. But I did not participate and cannot write about them.

Freitag, 15. Juni 2012

Advanced Python Course at EuroPython

Python is probably the easiest language to learn among the real-world programming languages. It is a good language for beginners and can be picked up very quickly by experienced programmers. You don't have to learn every detail of the language to write a simple script. You can learn more when your programs and needs grow.

Python also offers a few more advanced features such as decorators, descriptors or metaclasses. While it is really simple to use a decorator, writing one yourself can become a bit more involved. This is one of the things that I like about Python: Simple things are simple and complex things are still possible with reasonable effort. I think doing things pythonically also means applying more complex approaches, if appropriate, to make things simpler in the end. I think we can distinguish between an active use of advanced features like writing a decorator and a passive use like applying a decorator to a function.

I have talked to many people who have used Python for years. A majority of them actively used only a few of the advanced features, if at all. Obviously, you can write useful software without diving too deep into Python. But these advanced features can help to make your programs better.

I think it is well worth investing in learning more about what Python offers. It will help you to better understand how Python works. Some of the features are used by frameworks. Knowing how a framework works under the hood can be helpful, especially when something doesn't work as expected. In addition, it is always good to challenge your mind a bit with new knowledge.

I will be teaching the course Advanced Python at EuroPython. This very intensive one-day training covers:

  • Comprehensions
  • Decorators
  • Iterators and Generators
  • Context managers
  • Descriptors
  • Metaclasses

The objective is for you to understand the general concepts but also to see and apply hands-on examples for all topics. Furthermore, you will get a feeling when a complex solution helps you make your code easier to use and when it is better to keep it simple.

What are the prerequisites? You should have used Python for a while and consider yourself a intermediate level Python programmer. If you know all things our Python for Programmers course covers, you will be able to take full advantage of this advanced course. Bring your laptop with Python 2.7 or 3.2 installed and get a good sleep the night before.

When: Saturday, July 7,  2012. That is one day after the EuroPython conference talks and tutorials.
Where: At the EuroPython venue in Florence.
Note: It requires an extra registration.

Freitag, 4. Mai 2012

PyPy - New Sprint Location

PyPy is an amazing project. I still remember one of the early announcements that PyPy kind of works but is 1000 times slower than CPython. It didn't take long and the  numbers dropped to 100 times and 10 times slower. Today, PyPy is faster  than CPython for most tasks. This is especially true for larger numerical calculations in loops, where the just-in-time compiler (JIT) can speed up things by an order of magnitude or more.

Even though PyPy isn't used a lot in real-life projects yet, it is at the brink to become a usable choice as a Python implementation for a number of tasks. There are still many things to do, and we would like to help. Therefore, we decided to sponsor a PyPy sprint by providing space and the necessary infrastructure for a few days.

The  PyPy Sprint in Leipzig, Germany (June 22 - 27, 2012) is the first at this location. Leipzig is worth a trip. As the famous German poet Goethe put it in Faust I: "Leipzig is a little Paris." So if you would like to contribute to PyPy and like to see new places (or re-visit known ones), consider coming.

Donnerstag, 23. Februar 2012

Learn High Performance Computing with Python

HPC and Python

You need a programming language that is very close to the metal to get the most performance from the hardware, right? Well, there is more to it. Python (read CPython) is everything but close to the metal. However, it is very well suited for High Performance Computation (HPC). There are several reasons for this:
  • Python comes with powerful data structures that provide or encourage very effective algorithms
  • Python shines in connecting with other languages
  • Python can be used as an effective user interface
  • Development with Python is typically much faster than with low level languages

The course

We offer a course about HPC with Python June 11 - 15, 2012 at Python Academy in Leipzig, Germany.

Who should attend?

This course targets medium level Python programmers who would like to have it both: fast program execution and fast development. Participants should have solid Python knowledge. Alternatively, you can attend the course Python for Programmers (one is offered just the week before June 5 - 7, 2012) to be able to take full advantage of this course.
This course provides expert knowledge for Python in HPC for software developers, engineers, researchers and scientists in many fields who need all the speed they can get from a computer but at the same time would like to use a flexible and elegant programming language that is rated as one of the most productive of the popular languages in use today.

The content

Optimizing of Python Programs
Learn how to profile programs, choose the right data structures and algorithms for the right purpose and get some hands-on experience in making Python programs faster with comparable little modifications.
Python Extensions with Other Languages
Learn about options to connect Python to other languages starting form Python's C-API and hand-written extensions the tour looks a Cython, ctypes, SWIG, Jython, Ironpython, and even f2py to connect with Fortran.
Fast Code with the Cython Compiler
In-depth coverage of Cython with Cython core developer Stefan Behnel. No question about writing extensions and using external C libraries with Cython should remain unanswered after this day.
Numerical Calculations with NumPy
NumPy is the way to work with multi-dimensional numerical arrays in Python. It is fast and provides a high-level programmer interface. This course day teaches you all the basics.
Fast NumPy Processing with Cython
Working with NumPy you need to avoid loops over arrays to make your code fast. While NumPy provides indexing and other techniques to help you here, some types of algorithms are easier expressed with loops. Combining NumPy with Cython you can write fast loops.
Another topic is parallel programming with OpenMP to take advantage of multi core CPUs that become so common place these days.

Organizational things

Register here.

Freitag, 17. Februar 2012

PyCon Number Six

Its always fun again

I've been attending PyCon US every year since 2007. So the 2012 edition marks number six. I've taught two tutorials at every PyCon and will do so this year, which brings the total count to twelve tutorials. Even though the conference is fully sold out, you can still go for the tutorials.


My tutorial Faster Python Programs through Optimization on Wednesday, March 7, 2012 is the first in a series of four (see Tutorials III) that are concerned with making your Python programs faster. This is nice. I always had the feeling that three hours are not enough to cover this topic in enough detail. I've given this tutorial numerous times at PyCon US, OSCON and PyCon AsiaPacific as well as an one-day open course, always improving and updating my material. The room was always well filled with up to 50 or even 70 people. This year PyCon is much bigger than ever before and there will be significantly more people in my tutorial as well.
My second tutorial Plotting with matplotlib on Thursday, March 8, 2012 gives an introduction to the powerful matplotlib library. I teach this topic as part of my course Python for Scientists and Engineers and gave this tutorial twice at EuroSciPy in 2010 and 2011. Scientists just love matplolib but it can be useful for anybody who wants to generate good looking diagrams with just a few lines of Python.


This year I will be even more busy: I will give a talk about HDF5 with Python. HDF5 is the preferred way for many scientists to store large amounts of (numerical) data. But it can be interesting for other programmers too. Tons of data and no need for the relational part? You might want to have a look.


Another premiere this year. We are PyCon sponsor with our logo on the website, a tote bag insert and even a booth. So if you are interested in talking to me, just stop by at booth 322.