functional python: a simple infinite list example

The object oriented, “duck typed” programming language python has also some functional features on par with serious functional languages. One example for these advanced functional elements are the infinite lists (as generators and iterators): # sieve of Erastothenes from itertools import count from itertools import ifilter def sieve(possible_primes): yield next_prime for i in sieve(ifilter(lambda … Continue Reading

Developing Plone on Ubuntu 9.04 with virtualenv

zuletzt verändert: 18.02.2011 15:52 Technical notes to overcome some obstacles Ubuntu 9.04 “Jaunty Jackalope” removed python 2.4 libraries from the distribution, which are necessary to run Zope/Plone. To work in a more defined environment, where other as the system libraries are installed for a specific python, people use virtualenv. Install virtualenv, python-2.4 from the distribution … Continue Reading

svn: ‘…’ has no ancestry information

zuletzt verändert: 18.02.2011 15:52 subversion (1.6.5) and – depending on it – mr. developer complained about some strange missing ancestry information. I tried to commit code from this directory tree: toplevel/ .svn/ … 2ndlevel/ (no .svn here) … 3rdlevel/ .svn/ code_to_commit Trying cd 3rdlevel svn commit -m ‘bla’ produced the error svn: ‘2ndlevel’ has no … Continue Reading