Python Posts

133 posts tagged with python

I'd like to announce version 2.0.0 of PyFilesystem, which is now available on PyPi.

PyFilesystem is a Python module I started some time in 2008, and since then it has been very much a part of my personal standard library. I've used it in personal and professional projects, as have many other developers and organisations.

If you aren't familiar with PyFilesystem; it's an abstraction layer for filesystems. Essentially anything with files and directories (hard-drive, zip file, ftp server, network filesystems etc.) may be wrapped with a common interface. With it, you can write code that is agnostic as to where the files are physically located.

Here's a quick example that recursively counts the lines of code in a directory: continue reading…

It's not often I come across something in Python that surprises me. Especially in something as mundane as string operations, but I guess Python still has a trick or two up its sleeve.

Have a look at this string:

How many possible sub-strings are in s? To put it another away, how many values of x are there where the expression x in s is true?

Turns out it is 2.

2?

Yes, 2.

The empty string is in the string "A". In fact, it's in all the strings.

Turns out the empty string has been hiding every where in my code.

Not a complaint, I'm sure the rationale is completely sound. And it turned out to be quite useful. I had a couple of lines of code that looked something like this: continue reading…

This SO post prompted me to think about how you would go about customizing a entire Django site (not just an app). Particularly if it is a third party project, still in development.

Forking the site repository is a solution, but the more customizations you make, the more awkward it becomes to merge upstream fixes and features. The problem is compounded if you have multiple deploys, with custom templates, assets, and settings.

I wanted to do a quick write-up of how this would be done in Moya, where customization is more of a first-class concept.

I'll briefly go over how you would serve a Moya site with a custom template, without modifying any of the original files. The project I'll be customizing is Moya Techblog which power this blog. continue reading…

Inthing can take a screenshot of your desktop then post it online.

Here's a quick example:

Alternatively you can do the same thing from the command line with the inthing app. The following is equivalent to the Python code (assuming you have set up the stream and password environment variables):

See the docs for more details.

Screenshot capabilities courtesy of the excellent pyscreenshot library.

Screenshot taken with Stream.screenshot

Just landed in inthing is a new and quite interesting feature.

Version 0.1.4 adds a capture method which will record all standard output, i.e. anything you print to the terminal. It works as a context manager. Here's an example:

Any print statement inside the with block will be captured and posted online with the block exits.

You can also do something similar from the command line, with the inthing capture subcommand, which posts anything you pipe in to it as an event.

lets say you wanted to post the version of all you installed Python packages online. You could do something like the following:

For more information see the Inthing docs.

Inthing is still technically in beta, but these features are quite solid. Please give them a try, and let me know how it goes!

The Django code in this post comes from the official Django tutorial.

I've tried not to be disingenuous with the comparison, and I'm only going to compare like with like, so I can show code from both frameworks and let you draw your own conclusions. I'll cover the areas where they differ in another post.

Both Moya and Django use models to map databases on to familiar data structures. In the case of Moya, the mapping is done with SQLAlchemy. Django uses its own ORM.

Here's the models.py from the Django tutorial and a Moya version: continue reading…

One of my goals for inthing.io was to make posting events realtime, in that events appear without a page refresh, and within a fraction of a second. And that largely seems to work.

Here's a quick screencast that shows it working:

I'll post about how it works in detail at some point, but the general gist is that there is a Tornado websocket server that inthing uses to broadcast information about updates. That server may be worth open-sourcing if there is enough interest. It could be useful for other projects, and its entirely independent.

There a few options, but I'm going to suggest using the inthing Python module.

First install inthing with PIP. You'll probably know if you need to use sudo or not:

Now fire up Python, and enter the following (copy and paste each line after the >>> prompt):

So far so good. We now have a Stream object called stream, with a corresponding live page on the web. We'll have a look at that later, but lets first do something interesting with it. Enter the following function (copy and paste all the text after the >>>):

If that pasted correctly, we should have a function that generates the Mandlebrot set in ASCII. Add it to the stream with the following:

Finally, to get the URL of the stream, do this:

If you visit that URL, you should see the Mandlebrot set you just generated. continue reading…

I'm happy to announce release 0.6.0 of Moya.

Moya is a web-application platform written in Python. In that respect it is a lot like other Python frameworks such as Django, Pyramid, Flask, Bottle etc. Moya has versatile URL routing, a fast template language, an ORM, a forms library, i18n support, image processing, and a variety of other tools to build a modern web app. Where Moya differs from other Python frameworks in that Python is not required to make use of these features. continue reading…

Raspberry Pis are useful little computers. I own several, since I work with them in my day job, and I thought it was about time I put one to use.

I also happen to keep tropical insects. Specifically, beetles. These are not your garden variety beetles, unless you happen to live in a rain forest. The ones I have at the moment are elephant beetles which come from Central and South America. Here's a photo:

Male elephant beetle. Banana for scale.

These insects are mostly nocturnal. During the day they tend to burrow under their bedding material (moss), or hang out on a branch. But during the night, they can be quite active. I know this because in the morning they have re-arranged the branches in their tank. continue reading…