Question

The sampled code below is for the GUI I am currently making. I have two problems. The first problem is when I redirect the python output using the RedirectText class, the output is printed on the TextCtrl box (‘tc2’) only when the loop is finished, for that particular iteration. How do I get the text to print as it goes through the loop and not when its finished?

My second problem is i’m using a compiled fortran file EHSS_updated_atoms.out the output from this file prints to the terminal and not to the text control box. How do I get the the output from the compiled fortran file to the text control box? as it is printed to the terminal.

import wx
class RedirectText(object):
    def __init__(self,aWxTextCtrl):
        self.out=aWxTextCtrl

    def write(self,string):
        self.out.WriteText(string)



def __init__(self, *args, **kwargs):
    super(Example, self).__init__(*args, **kwargs) 

    self.InitUI()
    self.Centre()
    self.Show() 
    self.SetSize((800, 600))
    self.SetTitle('Hello')

def InitUI(self):
    import sys

    vbox = wx.BoxSizer(wx.VERTICAL)
    hbox5 = wx.BoxSizer(wx.HORIZONTAL)
    btn1 = wx.Button(panel, label='Run prog')
    hbox5.Add(btn1)
    btn2 = wx.Button(panel, label='Stop prog')
    hbox5.Add(btn2, flag=wx.LEFT|wx.BOTTOM, border=5)
    vbox.Add(hbox5, flag=wx.ALIGN_CENTER|wx.RIGHT, border=10)
    self.Bind(wx.EVT_BUTTON, self.prog, btn1)
    #self.Bind(wx.EVT_BUTTON, self.cancel_prog, btn2)


    hbox3 = wx.BoxSizer(wx.HORIZONTAL)
    tc2 = wx.TextCtrl(panel, style=(wx.TE_MULTILINE|wx.TE_READONLY))
    hbox3.Add(tc2, proportion=1, flag=wx.EXPAND)
    vbox.Add(hbox3, proportion=1, flag=wx.LEFT|wx.RIGHT|wx.EXPAND,border=10)
    redir=RedirectText(tc2)
    sys.stdout=redir
    sys.stderr=redir


    panel.SetSizer(vbox)

def prog(self, evt):
    import os
    import shutil
    import subprocess
    from mobcal_prep import mobcal

    extension = '.pdb'
    list_of_files = [file for file in os.listdir('%s' % _selectedDir) if file.lower().endswith(extension)]

    prep = mobcal()

    for pdb in list_of_files:
        print '### Running PDB: %s ###' % pdb
        prep.new_mobcal_format(pdb)
        subprocess.call(['./EHSS_updated_atoms.out', pdb[:-4]+'_new_mobcal.mfj',pdb[:-4]+'_new_mobcal.out'])
        prep.caluclate_average('%s_new_mobcal.out' % pdb[:-4], pdb)
        subprocess.call(['rm', pdb[:-4]+'_new_mobcal.out'])

Answer 1

When dealing with graphical interfaces, have into account that the program is basically running into a loop (the “main loop”), which among other things triggers events, etc. That’s the main thread of the program. If you do anything inside that thread (like calling EHSS_updated_atoms.out) that blocks the main loop for a while, there will be no changes on your interface until that is finished.

You can make this work by, for example, running the prog function in a separate thread. Check this forum post for a small example piece of code on how to do it. Note the hint to use wx.Yield() or wx.SafeYield() to make the interface more responsive.

Edit: forgot about the redirection.

You don’t need to redirect the whole sys.stdout and sys.stderr. subprocess.call admits two arguments just for that, so if you pass redir to the prog function, you can do:

call(.........., stdout = redir, stderr = redir)

Edit:

For the redirection, try this instead:

p subprocess.Popen(['./EHSS_updated_atoms.out', pdb[:-4]+'_new_mobcal.mfj',pdb[:-4]+'_new_mobcal.out'],
                   stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
for line in p.stdout:
    redir.write(line)
p.wait()