We'll be digging into Mastering Object-Oriented Python. Chapter 17, specifically.

We'll also be looking at a big refactoring of the Stingray Schema-Based File Reader.

We can identify three species of packages.

One common design is a Simple Package. A directory with an empty __init__.py file. This package name becomes …

Want a copy free? See this contest: http://www.blog.pythonlibrary.org/2014/05/12/ebook-contest-win-a-free-copy-of-mastering-object-oriented-python/.

If you're really interested, I can sign a copy. That will double the shipping cost, so perhaps that's not the best idea.

The bad news is that the errata have started to trickle in …

• 0 Some Preliminaries 3 examples, 56 lines
• 1 The __init__() Method 55 examples, 351 lines
• 2 Integrating Seamlessly …

Updates completed. See https://sourceforge.net/projects/pywebtool/ and http://pywebtool.sourceforge.net.

The list of changes is extensive.

However, the essential API and the markup language for creating literate programs hasn't (significantly) changed. A few experimental features were replaced with a first-class implementation.

The interesting (to me) bit is …

• Some small improvements to the COBOL DDE parsing.
• A sensible demo program that shows how to read COBOL files.
• A complete rewrite to Python3.3.
• Support for more COBOL syntax.
• Support for Occurs Depending On
• Support for RECFM=F, RECFM=V and RECFM=VB …

See this: SortedContainers — sortedcontainers 0.6.0 documentation

Here's some text from the invitation.

You may find the the performance comparison and implementation details interesting because it doesn't use any sophisticated tree data structure or balancing algorithms. It's a great example of taking advantage of what processors are good at …

Read this http://en.wikipedia.org/wiki/Einstellung_effect Great article in Scientific American on this.

I didn't realize that sometimes I do spend time trying to defeat the Einstellung effect. Not a lot of time. But some time.

When confronted with gnarly design problems, I have the same bad habits …

While wrestling with Python's shelve module, I ran across ACID. Interesting thoughts. Plus what appears to be the related Tumblr blog: python sweetness. Also interesting. Not sure I can make heavy use of it right now, but it's helpful to see the thought process. I find the subject of shelve …

Epiphany.

In Python, with iterators, the Visitor design pattern is useless. And a strongly-ingrained habit. Which I'm trying to break.

Here's a common Visitor approach:

class Visitor:
    def __init__( self ): ...
    def visit( self, some_target_thing ): ...
    def all_done( self ): ...

v = Visitor()
for thing in some_iterator():
    v.visit(thing)
v.all_done()

If we …