PyDev of the Week: Edward Ream

Ream: ​Piano, walking, science, literature, history. I read Science and Nature every week. I encourage your readers to do the same. Start with reading the summary articles and the abstract for each article. They are written for non-specialists. All scientists are lay people outside their immediate area!

I have taken piano and theory lessons for many years from Michael Butkus-Bormier. He knows approximately everything about music. He’s a great jazz and classical performer. And a close friend.

I regularly do laughter yoga. It’s easily the most transformative thing I have done, including the Hoffman Process and the Landmark Education Forum. I find that laughter helps me to connect with people and eases anxiety in social situations.

Laughter is a huge help to creativity.  I vividly remember a video of “Ham & Clyde” laughing while discussing their work with J. Craig Venter.  Alas, I can’t find the link. Oh btw, Ham is a Nobelist.

I walk regularly to solve problems.  The trick is to daydream. When any relevant thought appears I write it down in a 89 cent notebook. The idea is to forget what I have just written down so new thoughts appear. Trying to remember things kills further daydreaming.

Rebecca is my muse.  She’s a gardener and weaver, but she asks great questions when I talk to her about Leo, even especially technical questions. Think about how great that is!

The idea that I could use the MORE outliner as a prototype for (what became) Leo arose in conversation with her.  Very likely none of this would have happened without her.

I started learning Python in early 2001.  I went to the Pycon that year outside DC and got snowed on. It’s a strange feeling walking near the Capital and seeing no traffic.

Just this year I realized that it’s not about the javascript language. It’s about the tools.  So I’m learning about the node.js and vue.js world, driven by Leo’s devs.

pyflakes catches essentially all of my initial blunders. It’s so fast that I can configure Leo to run pyflakes whenever I save a .py file.  I configure Leo to raise a dialog when pyflakes detects an error 😉

Ream: I have struggled with this question from the beginning. Leo’s wikipedia page is a dry summary. Leo’s preface is another. But these might not help you or your readers much.

I could answer “sideways” by listing the great programmers who have contributed to Leo: Terry Brown, Brian Harry, Bernhard Mulder, Vitalije Milosevitch, Ville M. Vainio, etc. When I have doubts about Leo I remember them 🙂

You must use Leo to really understand it. We Leonistas talk about the Leonine World. Many people do get it:

“When first I opened Leo, it was out of curiosity. But having used it, I’ll never go back. They’ll have to pry Leo out of my cold, dead fingers!” Travers A. Hough

You will find similar sentiments throughout the What People are Saying about Leo page.

But still.  All this is indirect. As Vitalije pointed out recently, the real Aha is that Leo thoroughly connects outline structure with the code itself.

With Leo, code isn’t just text.  It lives in a “super duper outline”, namely a directed acyclic graph.  Such a data structure, and no other, allows simple definitions of clones.

Clones free outlines from static organization. Data, including parts of programs, can reside in arbitrarily many places in the same outline.  I use this all the time. I gather clones of the methods I am working so that I can see them clearly.  This eliminates a lot of searching. Leo’s clone-find commands leverage clones in a spectacular way, but I don’t want to overwhelm your readers 😉

All code/scripts have easy access to the outline in which they are embedded. Leo’s execute-script command defines three constants: c, g and p.  c is the gateway to all of Leo’s live code g is a python module containing lots of useful utils. Most importantly, p is the presently selected node in the outline. p.h is its headline. p.b is its body text. p.u is an arbitrarily extensible set of u’s (user-defined attributes).

Leonine scripts are scripts with automatic access to c, g and p.  To give you just a glimpse of the power of such scripts, here is the second “hello world” example. Put this in any Leo node and do Ctrl-B (execute-script):

for p in c.all_positions():
    print(p.level()*' ' + p.h)

It prints all the headlines in the outline, properly indented.

That’s the entire script. Notice the dogs that aren’t barking!

But this is just the beginning. The c constant, via easy to use methods on c, allows scripts to modify the outline in which they reside.  Some users, including my brother, use this to turn Leo into a database.