wxPython


The wxPython GUI toolkit includes its own date / time capabilities. Most of the time, you can just use Python’s datetime and time modules and you’ll be fine. But occasionally you’ll find yourself needing to convert from wxPython’s wx.DateTime objects to Python’s datetime objects. You may encounter this when you use the wx.DatePickerCtrl widget.

Fortunately, wxPython’s calendar module has some helper functions that can help you convert datetime objects back and forth between wxPython and Python. Let’s take a look:

def _pydate2wxdate(date):
     import datetime
     assert isinstance(date, (datetime.datetime, datetime.date))
     tt = date.timetuple()
     dmy = (tt[2], tt[1]-1, tt[0])
     return wx.DateTimeFromDMY(*dmy)
 
def _wxdate2pydate(date):
     import datetime
     assert isinstance(date, wx.DateTime)
     if date.IsValid():
          ymd = map(int, date.FormatISODate().split('-'))
          return datetime.date(*ymd)
     else:
          return None

You can use these handy functions in your own code to help with your conversions. I would probably put these into a controller or utilities script. I would also rewrite it slightly so I wouldn’t import Python’s datetime module inside the functions. Here’s an example:

import datetime
import wx
 
def pydate2wxdate(date):
     assert isinstance(date, (datetime.datetime, datetime.date))
     tt = date.timetuple()
     dmy = (tt[2], tt[1]-1, tt[0])
     return wx.DateTimeFromDMY(*dmy)
 
def wxdate2pydate(date):
     assert isinstance(date, wx.DateTime)
     if date.IsValid():
          ymd = map(int, date.FormatISODate().split('-'))
          return datetime.date(*ymd)
     else:
          return None

You can read more about this topic on this old wxPython mailing thread. Have fun and happy coding!

I’ve been using wxPython for quite a while now and I see certain questions come up on a fairly frequent basis. One of the popular ones is how to ask the user for their credentials before loading up the rest of the application. There are several approaches to this, but I am going to focus on a simple solution as I believe this solution can be used as the basis for more complex solutions.

Basically what we want to happen is for the user to see a login dialog where they have to enter their username and password. If they enter it correctly, then the program will continue to load and they’ll see the main interface. You see this a lot on websites with a common use case being web email clients. Desktop applications don’t include this functionality as often, although you will see it for Stamps.com’s application and for law enforcement software. We will be creating a dialog that looks like this:

wxLogin.png (more…)

The wxPython Google Group was discussing different methods of catching exceptions in wxPython the other day. If you use wxPython a lot, you will soon realize that some exceptions are difficult to catch. The wxPython Wiki explains why. Anyway, the fellows on the list were recommending the use of sys.excepthook. So I took one of the methods they mentioned and created a little example: (more…)

The other day someone was asking a lot of questions on StackOverflow about how to work with wizards in wxPython. You can read the two original questions here and here. The code we’ll be looking at in this example is what I used to answer the questions on Stack. The primary question was how to disable the Next in a wxPython wizard. (more…)

One of my friends on the wxPython Google Group asked how to catch any exception that happens in wxPython. The problem is complicated somewhat because wxPython is a wrapper on top of a C++ library (wxWidgets). You can read about the issue on the wxPython wiki. Several wxPython users mentioned using Python’s sys.excepthook to catch the errors. So I decided to write up an example showing how that worked based on something that Andrea Gavana posted on the aforementioned thread. We will also look at the solution that is in that wiki link. (more…)

I’ve been thinking about creating a simple downloading script with wxPython for quite a while. Then I saw someone on StackOverflow asking about how to do it and I decided it was time to figure it out. Downloading a file with Python is trivial. I wrote about a couple of different ways to do that in a previous article. The big question was how to do it in such a way that I could update the UI as the file was downloading. It’s actually pretty easy and this article will show you how! (more…)

The wxPython toolkit provides an alternative to using Sizers for layout that is known as “sized_controls”. These controls or widgets are basically top-level widgets (like frame, panel, dialog, etc) that have sizing logic built into them. This article will cover all four types of sized_controls. They are as follows:

  • SizedPanel
  • SizedScrolledPanel
  • SizedFrame
  • SizedDialog

The SizedScrolledPanel widget is new as of wxPython 2.9.3.1, but the other 3 types of controls are available in wxPython 2.8.8 and possibly older versions (see Trac for more info). Just keep that in mind if you are on wxPython 2.8. If you are ready, we can get started! (more…)

wxPython 2.9 introduced the world to a new type of sizer that can take widgets and automatically make them “wrap” around as you resize the frame. That sizer is known as wx.WrapSizer. For some reason, it is relatively unknown, so we’ll spend a few minutes going over how to use it in this article.

To follow along with this tutorial, you will need to have wxPython 2.9 or greater. Once you’ve got that, we can continue. (more…)

Really Simple Syndication (RSS) has been with us for a long time and allows us to see new articles on our favorite website easily. Python doesn’t have an RSS reader module in the standard library, so we’ll be using the Universal Feed Parser 5.1.3 to do our parsing. If you do not have it already, you should go download it from the Python Package Index now. We’ll use this blog’s RSS feed to make testing simpler. The url for the feed is: http://www.blog.pythonlibrary.org/feed/. During my experiments, I noticed that my blog software will change a dash into the following unicode character: \u2013. This will cause feedparser to throw a UnicodeEncodeError, so I also recommend downloading the handy unidecode module to help with that. (more…)

This week I saw a question on StackOverflow about putting two grids into a SplitterWindow which itself was in a Notebook page. Personally I think that’s a little convoluted, but I thought it was an interesting challenge and I came up with a solution. Then the fellow wanted to know how to sync the scrolling of the two grids. Well, I found an answer and modified my code and decided it was worth writing an article about. (more…)

Next Page »