Category Archives: GUI Toolkits

An Intro to StaticBox and StaticBoxSizers

There are many widgets that are included with the wxPython GUI toolkit. One of them is a fairly handy widget called wx.StaticBox. This widget accepts a string and then will draw a box with the string in the upper left-hand corned of the box. However this only works when you use it in conjunction with wx.StaticBoxSizer.

Here is an example of what one might look like:

Simple wx.StaticBox

Now let’s go ahead and write the code you would use to create the example above: Continue reading An Intro to StaticBox and StaticBoxSizers

Creating a GUI Application for NASA’s API with wxPython

Growing up, I have always found the universe and space in general to be exciting. It is fun to dream about what worlds remain unexplored. I also enjoy seeing photos from other worlds or thinking about the vastness of space. What does this have to do with Python though? Well, the National Aeronautics and Space Administration (NASA) has a web API that allows you to search their image library.

You can read all about it on their website.

The NASA website recommends getting an Application Programming Interface (API) key. If you go to that website, the form that you will fill out is nice and short.

Technically, you do not need an API key to make requests against NASA’s services. However they do have rate limiting in place for developers who access their site without an API key. Even with a key, you are limited to a default of 1000 requests per hour. If you go over your allocation, you will be temporarily blocked from making requests. You can contact NASA to request a higher rate limit though.

Interestingly, the documentation doesn’t really say how many requests you can make without an API key.

The API documentation disagrees with NASA’s Image API documentation about which endpoints to hit, which makes working with their website a bit confusing.

For example, you will see the API documentation talking about this URL:

  • https://api.nasa.gov/planetary/apod?api_key=API_KEY_GOES_HERE

But in the Image API documentation, the API root is:

  • https://images-api.nasa.gov

For the purposes of this tutorial, you will be using the latter. Continue reading Creating a GUI Application for NASA’s API with wxPython

wxPython 4 and PubSub

The Publish-Subscribe pattern is pretty common in computer science and very useful too. The wxPython GUI toolkit has had an implementation of it for a very long time in wx.lib.pubsub. This implementation is based on the PyPubSub package. While you could always download PyPubSub and use it directly instead, it was nice to be able to just run wxPython without an additional dependency.

However, as of wxPython 4.0.4, wx.lib.pubsub is now deprecated and will be removed in a future version of wxPython. So now you will need to download PyPubSub or PyDispatcher if you want to use the Publish-Subscribe pattern easily in wxPython.


Installing PyPubSub

You can install PyPubSub using pip.

Here’s how to do it:

pip install pypubsub

PyPubSub should install quite quickly. Once it’s done, let’s find out how to use it! Continue reading wxPython 4 and PubSub

How to Distribute a wxPython Application

Let’s say you finished up a wonderful GUI application using wxPython. How do you share it with the world? This is always the dilemma when you finish an amazing program. Fortunately, there are several ways you can share your code. If you want to share your code with other developers, than Github or a similar website is definitely a good way to do. I won’t be covering using Git or Mercurial here. Instead what you will learn here is how to turn your application into an executable.

By turning your code into an executable, you can allow a user to just download the binary and run it without requiring them to download Python, your source code and your dependencies. All of those things will be bundled up into the executable instead.

There are many tools you can use to generate an executable:

You will be using PyInstaller in this tutorial. The main benefit to using PyInstaller is that it can generate executables for Windows, Mac and Linux. Note that it does not support cross-compiling. What that means is that you cannot run PyInstaller on Linux to create a Windows executable. Instead, PyInstaller will only create an executable for the OS that it is ran on. In other words, if you run PyInstaller on Windows, it will create a Windows executable only. Continue reading How to Distribute a wxPython Application

wxPython: Set Which Display the Frame is on

The other day, I saw an interesting question in the wxPython IRC channel. They were asking if there was a way to set which display their application would appear on. Robin Dunn, the creator of wxPython, gave the questioner some pointers, but I decided to go ahead and write up a quick tutorial on the topic.

The wxPython toolkit actually has all the bits and pieces you need for this sort of thing. The first step is getting the combined screen size. What I mean by this is asking wxPython what it thinks is the total size of the screen. This would be the total width and height of all your displays combined. You can get this by calling wx.DisplaySize(), which returns a tuple. If you would like to get individual display resolutions, then you have to call wx.Display and pass in the index of the display. So if you have two displays, then the first display’s resolution could be acquired like this:

index = 0
display = wx.Display(index)
geo = display.GetGeometry()

Let’s write up a quick little application that has a single button that will just switch which display the application is on. Continue reading wxPython: Set Which Display the Frame is on

How to Use wxPython Demo Code Outside the Demo

Every now and then, someone will ask about how they can run the demo code from wxPython’s demo outside of the demo. In other words, they wonder how you can extract the code from the demo and run it in your own. I think I wrote about this very topic quite some time ago on the wxPython wiki, but I thought I should write on the topic here as well.


What to do about the log

The first issue that I always see is that the demo code is riddled with calls to some kind of log. It’s always writing to that log to help the developer see how different events get fired or how different methods get called. This is all well and good, but it makes just copying the code out of the demo difficult. Let’s take the code from the wx.ListBox demo as an example and see if we can make it work outside of the demo. Here is the demo code: Continue reading How to Use wxPython Demo Code Outside the Demo

wxPython Recipes Book Contest

I recently had my self-published book, “wxPython Cookbook” picked up by Apress and republished as wxPython Recipes. Since they gave me a few complimentary paperback copies, I have decided to do a little contest.

Rules

  • Post a comment telling me why you would want a copy
  • The most clever or heartfelt commenter will be chosen by me

The contest will run starting now until Monday, January 15th @ 11:59 p.m. CST.

The winner will be contacted by yours truly and I will sign the book and ship it wherever you want me to.

For those of you who want to purchase the book, Apress gave me a lame 20% off coupon that you can use for either the eBook or Paperback on their website: wx20

wxPython Recipes Book Release

I was contacted earlier this year by Apress about republishing my book, wxPython Cookbook, under their branding. I thought it might be fun to see what I could learn from a publisher so I went with them as I have enjoyed several of their books in the past. The biggest change to the book is that I ended up grouping recipes into chapters instead of having each recipe be a stand-alone chapter. I also added a few new recipes to help fill in when some chapters weren’t easily sorted into groups.

Anyway, Apress just released the book in the past couple of days:

You can find the book over on Amazon or on the Apress website. You can also see a preview of the book on Google.

You can get 20% off of the book from Apress by using the following code: wx20. This code is good on the paperback and the eBook versions of the book until June 2018.

The code for the book is hosted on Apress’s Github account. I also host a copy on Github.

Regardless, feel free to check it out. If you already bought a copy of the wxPython Cookbook, then you don’t need to get this one too since it’s basically the same thing with a bit more polish and a handful of new recipes. I have plans for some other books that I will be self-publishing hopefully in 2018, so keep an eye on the blog for news about that!

wxPython: Drag and Drop an Image onto Your Application

I recently came across a question on StackOverflow where the user wanted to know how to drag images onto their image control in wxPython and have the dragged image resize into a thumbnail. This piqued my interest and I decided to figure out how to do it.

I knew that you could create a thumbnail in Python using the Pillow package. So if you’d like to follow along you will need to install Pillow and wxPython with pip:

pip install Pillow wxPython

Now that we have the latest versions of the packages we need, we can write some code. Let’s take a look: Continue reading wxPython: Drag and Drop an Image onto Your Application

wxPython: All About Accelerators

The wxPython toolkit supports using keyboard shortcuts via the concept of Accelerators and Accelerator Tables. You can also bind directly to key presses, but in a lot of cases, you will want to go with Accelerators. The accelerator gives to the ability to add a keyboard shortcut to your application, such as the ubiquitous “CTRL+S” that most applications use for saving a file. As long as your application has focus, this keyboard shortcut can be added trivially.

Note that you will normally add an accelerator table to your wx.Frame instance. If you happen to have multiple frames in your application, then you may need to add an accelerator table to multiple frames depending on your design.

Let’s take a look at a simple example: Continue reading wxPython: All About Accelerators