I want to use a regex to check for files that have spaces in the name and replace the spaces with underscores

Question

I wrote an app that uses ffmpeg to convert files to different fomat in a particular folder. The folder hosts .mpg, .mp3, .avi, .flv ... or whatever audio/video files one decides to add. The problem occurs when I use my app to select a file to convert that has spaces in the name; the app closes immediately, without having converted the file to a different format. Currently, I have to rename any files that has spaces in the name before it will convert via my app->ffmpeg. I'm attempting to write a function that will from the start of my app check file names in a particular folder for spaces, replace those spaces with underscores ('_'). I'm having some trouble with regex; I'm not good at writing/configuring them to solve problems. Can someone advise me on the correct regex to use to find white/blank space in a file name? Below is what I have so far:

import os
import re


pattern = r"([^\s]+(?=\.(mp3|mov|mpg|mp4|flv|avi|mpeg4|mkv|mpeg|mpg2|.wav))\.\2)"


def replace_Wspace(self, fName):
    if re.match(pattern, fName):
        fname = fName.replace(' ', '_')
    return fname

I'm adding the section of code from my app that handles the call to ffmpeg, as requested:

def convertButton(self, e):

    unit1 = self.format_combo1.GetValue()
    #Media Formats
    unit2 = self.format_combo2.GetValue()
    unit3 = self.format_combo3.GetValue()
    unit4 = None
    unit5 = self.format_combo5.GetValue()
    bitRate = self.format_combo6.GetValue()
    unit6 = bitRate
    if unit3 == '-qmax':
        unit4 = self.format_combo4.GetValue()
    else:
        pass

    os.chdir("c:\\d-Converter\\ffmpeg\\bin")
    wrkdir = os.getcwd()

    newfile = unit1
    stripped = newfile.strip('mpeg3aviovfl4w2c.') #Strips the extension from the original file name


    progname='c:\\d-Converter\\ffmpeg\\bin\\ffmpeg.exe' + ' -i '

    preset1_a='-vn -ar 44100 -ac 2 -ab'
    preset1_b='-f mp3 '
    preset_mp3='.mp3'

    chck_unit1 = self.my_endswith(unit1)



    while True:    
        if unit5 == 'video to mp3':

            if unit6 == 'k/bs' or unit6 == '':
                amsg = wx.MessageDialog(None, 'You must select a bit rate.', 'Media Converter', wx.ICON_INFORMATION)
                amsg.ShowModal()
                amsg.Destroy()
                break

            elif unit5 == 'video to mp3' and unit6 != 'k/bs' or unit6 != '':
                self.button.Disable()
                self.button2.Enable()
                self.format_combo1.Disable()
                self.format_combo2.Disable()
                self.format_combo3.Disable()
                self.format_combo4.Disable()
                self.format_combo5.Disable()
                self.format_combo6.Disable()
                startWorker(self.LongTaskDone, self.LongTask3, wargs=(progname, wrkdir, unit1, preset1_a, unit6, preset1_b, stripped, preset_mp3))
                break
            elif unit1 != unit1.endswith(".mpg") or unit1.endswith(".mpeg") or unit1.endswith(".avi") or unit1.endswith(".mp4") or unit1.endswith(".flv"):
                bmsg = wx.MessageDialog(None, 'You must select a valid format to convert to .mp3.', 'Media Converter', wx.ICON_INFORMATION)
                bmsg.ShowModal()
                bmsg.Destroy()
                break

        else:
            pass



        if unit1 == 'Select Media' or unit1 == '':
            amsg = wx.MessageDialog(None, 'You must select a media file!', 'Media Converter', wx.ICON_INFORMATION)
            amsg.ShowModal()
            amsg.Destroy()
            break


        elif unit2 == 'Select Format' or unit2 == '' or unit2 == chck_unit1:
            amsg = wx.MessageDialog(None, 'You must select a valid format', 'Media Converter', wx.ICON_INFORMATION)
            amsg.ShowModal()
            amsg.Destroy()
            break


        elif unit3 == 'Select Quality' or unit3 == '':
            amsg = wx.MessageDialog(None, 'You must select quality', 'Media Converter', wx.ICON_INFORMATION)
            amsg.ShowModal()
            amsg.Destroy()
            break

        elif unit3 != 'Select Quality' or unit3 != '':
            self.format_combo5.Disable()

            if unit3 == '-qmax':
                if unit4 == '0' or unit4 == '':
                    amsg = wx.MessageDialog(None, 'You must select number between 1-8.', 'Media Converter', wx.ICON_INFORMATION)
                    amsg.ShowModal()
                    amsg.Destroy()
                    break
                else:
                    self.button.Disable()
                    self.button2.Enable()
                    self.format_combo1.Disable()
                    self.format_combo2.Disable()
                    self.format_combo3.Disable()
                    self.format_combo4.Disable()
                    self.format_combo5.Disable()
                    startWorker(self.LongTaskDone, self.LongTask2, wargs=(progname,wrkdir,unit1,unit3,unit4,stripped,unit2))
                    break
            elif unit3 == '-sameq':
                self.button.Disable()
                self.button2.Enable()
                self.format_combo1.Disable()
                self.format_combo2.Disable()
                self.format_combo3.Disable()
                self.format_combo4.Disable()
                self.format_combo5.Disable()
                startWorker(self.LongTaskDone, self.LongTask, wargs=(progname,wrkdir,unit1,unit3,stripped,unit2))
                break   




def LongTask(self, progname, wrkdir, unit1, unit3, stripped, unit2):
    convert_file1 = progname + wrkdir + '\\' + unit1 + ' ' + unit3 + ' ' + stripped + unit2
    self.statusbar.SetStatusText("Converting: " + unit1 + "...")
    os.system(convert_file1)
    print convert_file1


def LongTask2(self, progname, wrkdir, unit1, unit3, unit4, stripped, unit2):
    convert_file2 = progname + wrkdir + '\\' + unit1 + ' ' + unit3 + ' ' + unit4 + ' ' + stripped + unit2
    self.statusbar.SetStatusText("Converting: " + unit1 + "...")
    os.system(convert_file2)


def LongTask3(self, progname, wrkdir, unit1, preset1_a, unit6, preset1_b, stripped, preset_mp3):
    convert_file3 = progname + wrkdir + '\\' + unit1 + ' ' + preset1_a + ' ' + unit6 + ' ' + preset1_b + stripped + preset_mp3
    self.statusbar.SetStatusText("Converting: " + unit1 + "...")
    os.system(convert_file3)
    print convert_file3

def LongTask4(self, progdir, wrkdir, prog_dir, progdir3, f_string, s_string2, vid_format):
    convert_file4 = progdir + f_string + prog_dir + s_string2 + progdir3 + f_string.strip('mpegaviw24ofl.') + vid_format
    self.statusbar.SetStatusText("Converting: " + f_string + "...")
    os.system(convert_file4)
    print convert_file4

Answer 1

F.J's answer is great. If you are really concerned about spaces, and you do want to change them like iTunes does, I would only add that you may want to do something like this:

audio = ('.mp3','.mov','.mpg','.mp4','.flv','.avi','.mpeg4','.mkv','.mpeg','.mpg2','.wav')
spaces=['\t',' ','\r','\n','\v']  # etc -- other nasty space like characters...
if fName.endswith(audio) and any(space in fName for space in spaces):
    return ''.join(c if c not in spaces else '_' for c in fName)
...

The you are catching all potential space like characters in fName into '_'

So if you have:

fName='file name\twith\nstuff\vin it'

it turns into:

file_name_with_stuff_in_it     

Answer 2

Instead of regex, use use fName.endswith(), you can provide a tuple as an argument of all of your audio extensions and it will return True if fName ends with any of them, for example:

audio = ('.mp3','.mov','.mpg','.mp4','.flv','.avi','.mpeg4','.mkv','.mpeg','.mpg2','.wav')
if fName.endswith(audio) and ' ' in fName:
    return fName.replace(' ', '_')
return fName

If there are no spaces or it has a different extension, it will return the original string without changes.

Alternatively, you could use os.path.splitext():

audio = set(('.mp3','.mov','.mpg','.mp4','.flv','.avi','.mpeg4','.mkv','.mpeg','.mpg2','.wav'))
if os.path.splitext(fName)[1] in audio and ' ' in fName:
    return fName.replace(' ', '_')
return fName

Answer 3

I don't think you need regex for this. You can simply use if ' ' in file:

Like so:

import os
dir = '.'
for file in os.listdir(dir)
  if ' ' in file:
    os.rename(file,file.replace(' ','_'))

Might want to print file to test that you're in the right directory, before you try a mass rename.

If you need to make sure it's an acceptable file format, use os.path.splitext() to get the extension:

extensions = ('.mp3','.mov','.mpg','.mp4','.flv','.avi','.mpeg4','.mkv','.mpeg','.mpg2','.wav')
fname, ext = os.path.splitext(file)
if ext in extensions:
  ...