import this

10. January, 2014

During the Flask presentation yesterday, I learned about an Easter egg in Python: “import this” which will print:

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!


Comfortable Access to Config Options in Python

12. October, 2012

I always felt that Python’s ConfigParser API could be better. I like to access my config options like this:

    self.config.option

To solve this, I wrote ConfigProvider which can copy options from ConfigParser into a Python instance:

class ConfigProvider:
    __doc__ = 'Interface which can copy values from ConfigParser into a config object'
    
    def __init__(self, cfg):
        self.cfg = cfg
    
    def update(self, section, cfg):
        __doc__ = 'Updates values in cfg with values from ConfigParser'
        
        for name, value in inspect.getmembers(cfg):
            if name[0:2] == '__' or inspect.ismethod(value):
                continue
            
            #print name
            if self.cfg.has_option(section, name):
                setattr(cfg, name, self.cfg.get(section, name))

The magic happens in update() which examines the config object that you pass in and which copies the values from the external ConfigParser into it.

The gist “Comfortable config access with Python” contains the whole code and a demo.


Boo

8. July, 2011

It seems a dream of mine has come true: A language like Python, compiled into something that can be executed as fast as Java or C++ and which allows to extend the compiler at compile time.

Ladies and gentlemen, please a warm welcome for Boo.

Guess I’ve found a reason to install Mono.


Maven Tools for Eclipse: M2 Repository Analysis And Dependency Management

13. May, 2011

I’ve finished RC1 of my set of tools to import Eclipse plug-ins into Maven 2 repositories. You can find the source on github. It needs Python 2.7 and lxml. pip is your friend.

The new features: There is now a tool to analyze the M2 repository for oddities. Currently, it can find these issues:

  • Dependencies which are used but not part of the repository
  • Dependencies which are used with different versions or version ranges (i.e. when one POM includes a dependency with 1.0 and another POM pulls in the very same dependency with version 1.1)
  • Dependencies which are used without versions or version ranges or a catch-all version like [0,)
  • Several versions of the same artifact in the repository

Plus it prints a list of all POMs in the repo with files (jar, pom, sources, test-sources, …). Here is a sample report.

The last tool can create a POM file with a dependencyManagement element containing the versions of the POMs in the repository. You can use this to nail down all versions to the ones existing in your repository (so you don’t accidentally pull in something you don’t want).

Lastly, I’ve enhanced the patch tool. Instead of overwriting replaced dependencies, it will now move them into a new profile. This way, users of the repository can specify which dependency they want (the one from the repository or, say, one from Maven Central).

I will try to build a new testing repo over the weekend so we can start wrapping up the necessary patches for a release.

Related posts: Eclipse 3.6.2 Artifacts for Maven 2


Numpty Physics

17. March, 2011

I really liked Crayon Physics. It was simple idea, great brain teaser, the perfect UI.

If you liked it as well, have a look at Numpty Physics.


pygments syntax highlighting

4. January, 2011

Need a good syntax highlighter? Check out Pygments.


The Python Module of the Week Blog

17. March, 2010

If you love Python, this blog is for you: Doug Hellmann posts about one Python module every week (PyMOTW). The posts contain lots of real world examples how to use a module. This week, it’s ElementTree.