wxPython: Showing 2 Filetypes in wx.FileDialog

The other day on the wxPython IRC channel on freenode, one of the members there asked if there was a way to make the wx.FileDialog display more than one file type at a time. In the back of mind, I thought I had seen a Microsoft product that could do it, but I'd never seen any wxPython examples. In this short tutorial, you will learn how to do this handy trick!

Here's the code you'll need:

import wx

wildcard = "Python source (*.py; *.pyc)|*.py;*.pyc|" \
         "All files (*.*)|*.*"

########################################################################
class MyForm(wx.Frame):
 
    #----------------------------------------------------------------------
    def __init__(self):
        wx.Frame.__init__(self, None, wx.ID_ANY,
                          "Multi-file type wx.FileDialog Tutorial")
        panel = wx.Panel(self, wx.ID_ANY)
        
        btn = wx.Button(panel, label="Open File Dialog")
        btn.Bind(wx.EVT_BUTTON, self.onOpenFile)
        
     #----------------------------------------------------------------------
    def onOpenFile(self, event):
        """
        Create and show the Open FileDialog
        """
        dlg = wx.FileDialog(
            self, message="Choose a file",
            defaultFile="",
            wildcard=wildcard,
            style=wx.OPEN | wx.MULTIPLE | wx.CHANGE_DIR
            )
        if dlg.ShowModal() == wx.ID_OK:
            paths = dlg.GetPaths()
            print "You chose the following file(s):"
            for path in paths:
                print path
        dlg.Destroy()
        
#----------------------------------------------------------------------
# Run the program
if __name__ == "__main__":
    app = wx.App(False)
    frame = MyForm()
    frame.Show()
    app.MainLoop()

The key in this code is in the wildcard variable. Look closely at it and you'll notice that there's some semi-colons in there. The semi-colon in the second half of the first string is what we care about. It tells the dialog to just show *.py and *.pyc files. Yes, it really is that simple. The first half can be anything you want, but it is recommended that you tell your users what file types they can expect it to return.

That's all there is to it. Be sure to keep this trick in the back of your mind when you go to create your own file dialogs. You might just need it!