fix traceback issue with quit()

make script more readable using functions
add function descriptions
add more user prints and guidance
perform manual integration tests

Author: Schallbert

AutoStructureFilesForDFplayer.py

@@ -1,137 +1,159 @@
-import os, os.path
+import os
+from sys import exit
+import os.path
 import shutil
 
-#this function pads leading zeros to a number, returning a string.
-def playerFSnumbers(folderIndex, maxCnt):
-    if folderIndex > maxCnt:
-        print("Error: player cannot process more than 100 folders")
-        input("Press Enter to quit...")
-        quit()
-    return str(folderIndex).zfill(len(str(maxCnt)))
+#Author: L. Preusser "Schallbert"
 
-#folder names
+# this function pads leading zeros to a number, returning a string.
+def playerFSnumbers(indx, maxCnt):
+    """This function returns a DFplayerMini-compatible way of numbering
+    files which is 001, 002, ... 255"""
+    if indx > maxCnt:
+        quitWithMessage("Error: player cannot process more than 100 folders")
+    return str(indx).zfill(len(str(maxCnt)))
+
+def replaceSpecialCharactersInPlaylist(lineOfPlaylist):
+    """Make sure .m3u file's special characters are converted
+    Replace most commont HTML exclamations"""
+    lineOfPlaylist = lineOfPlaylist.replace("%20", " ")
+    lineOfPlaylist = lineOfPlaylist.replace("%21", "!")
+    lineOfPlaylist = lineOfPlaylist.replace("%22", '"')
+    lineOfPlaylist = lineOfPlaylist.replace("%23", "#")
+    lineOfPlaylist = lineOfPlaylist.replace("%24", "$")
+    lineOfPlaylist = lineOfPlaylist.replace("%25", "%")
+    lineOfPlaylist = lineOfPlaylist.replace("%26", "&")
+    lineOfPlaylist = lineOfPlaylist.replace("%27", "'")
+    lineOfPlaylist = lineOfPlaylist.replace("%28", "(")
+    lineOfPlaylist = lineOfPlaylist.replace("%29", ")")
+    lineOfPlaylist = lineOfPlaylist.replace("%2A", "*")
+    lineOfPlaylist = lineOfPlaylist.replace("%2B", "+")
+    lineOfPlaylist = lineOfPlaylist.replace("%2C", ",")
+    lineOfPlaylist = lineOfPlaylist.replace("%2D", "-")
+    lineOfPlaylist = lineOfPlaylist.replace("%2E", ".")
+    lineOfPlaylist = lineOfPlaylist.replace("%2F", "/")
+    lineOfPlaylist = lineOfPlaylist.replace("%3A", ":")
+    lineOfPlaylist = lineOfPlaylist.replace("%3B", ";")
+    lineOfPlaylist = lineOfPlaylist.replace("%3C", "<")
+    lineOfPlaylist = lineOfPlaylist.replace("%3D", "=")
+    lineOfPlaylist = lineOfPlaylist.replace("%3E", ">")
+    lineOfPlaylist = lineOfPlaylist.replace("%3F", "?")
+    return lineOfPlaylist
+
+def quitWithMessage(messageString):
+    """Quits script gracefully with message"""
+    print(messageString)
+    input("Press Enter to quit...")
+    sys.exit()
+
+print("\
+Starting Conversion script for structuring files for DFplayerMini.\n\
+This script analyzes .m3u playlists and restructures their contents to a format\n\
+readable by the DFmini mp3 module.\n\n")
+
+# folder names
 plFldrName = "PlayListsM3U"
 crdFldrName = "SDcardFolders"
-#player's maximum accepted file cnt
+# player's maximum accepted file cnt
 maxFldrCnt = 99
 maxFileCnt = 255
+listOfPlaylists = None
 
-#get current working directory
+# get current working directory
 myPath = os.getcwd()
-#create directories for playlists and target folders
+# create directories for playlists and target folders
 plPath = os.path.join(os.sep, myPath, plFldrName)
 crdPath = os.path.join(os.sep, myPath, crdFldrName)
-listOfPlaylists = None
 tgtFldrPath = -1
 tgtFileName = -1
 
-#Check for playlist path
+print("Hooked to current working directory: %s" % myPath)
+
+# Check for playlist path
 if not os.path.exists(plFldrName):
-    print("Did not find folder containing m3u playlists.\nTrying to create folder 'PlayListsM3U' for you.\nPlease move your playlists to this place before restarting the script.")
+    print("\
+Did not find folder containing m3u playlists.\n\
+Trying to create folder 'PlayListsM3U' for you.")
     try:
         os.makedirs(plFldrName)
     except:
-        print("Couldn't create folder. Is directory read-only?")
-        input("Press Enter to quit...")
-        quit()
+        quitWithMessage("Couldn't create folder. Is directory read-only?")
+    quitWithMessage("\
+Playlist folder successfully created: %s\n\
+Please move your playlists to this place before restarting the script." % plFldrName)
 else:
-    #if Playlist folder exists, print playlists to be evaluated.
+    # if Playlist folder exists, print playlists to be evaluated.
     listOfPlaylists = os.listdir(plFldrName)
     listOfPlaylists.sort()
     print("Folder containing playlists found. Will try creating DFplayer folders and files for:")
     print(listOfPlaylists)
-    #input("Press Enter to continue...")
-    
-#Check for album(folder) path
+# input("Press Enter to continue...")
+
+# Check for album(folder) path
 if not os.path.exists(crdFldrName):
-    print("Did not find folder containing SD card MP3 folders.\nTrying to create folder 'SDcardFolders' for you.\nYou will find the files to transfer to Tonuino in this folder.")
+    print("\
+Did not find folder containing SD card MP3 folders.\n\
+Trying to create folder 'SDcardFolders' for you.\n \
+You will find the files to transfer to your DFplayerMini's SD card in this folder.")
     try:
         os.makedirs(crdFldrName)
     except:
-        print("Couldn't create folder. Is directory read-only?")
-        input("Press Enter to quit...")
-        quit()
+        quitWithMessage("Couldn't create folder. Is directory read-only?")
 else:
-    #if Playlist folder exists, print playlists to be evaluated.
+    # if Playlist folder exists, print playlists to be evaluated.
     listOfCardFolders = os.listdir(crdFldrName)
     print("Folder containing SDcard MP3 folders found. Will modify folder structure based on playlist input.")
-    print(listOfCardFolders)
+    print("Existing folders: " + str(listOfCardFolders))
 
-#create folders with correct naming to contain mp3 files
+# create folders with correct naming to contain mp3 files
 folderIndex = 0
 fName = ""
 lineLower = ''
-if listOfPlaylists is not None:
-    print(listOfPlaylists)
-    #Go through all .m3u files in .m3u folder
+if listOfPlaylists:
+    print("Playlists found: " + str(listOfPlaylists))
+    # Go through all .m3u files in .m3u folder
     for item in listOfPlaylists:
         os.chdir(crdPath)
         folderIndex += 1
-        #get folderIndexes right according to player's needs
+        # get folderIndexes right according to player's needs
         fName = playerFSnumbers(folderIndex, maxFldrCnt)
         if not os.path.exists(fName):
             try:
                 os.makedirs(fName)
             except:
-                print("Couldn't create folder. Is directory read-only?")
-                input("Press Enter to quit...")
-                quit()
+                quitWithMessage("Couldn't create folder. Is directory read-only?")
         else:
-            #folder already exists. Auto-Overwrite.
-            print("Folder '%s' exists. Will auto-overwrite contents." % (fName,))
-        #go through all playlists in folder
+            # folder already exists. Auto-Overwrite.
+            print("Folder '%s' exists. Will auto-overwrite contents." % fName)
+        # go through all playlists in folder
         tgtFldrPath = os.path.join(os.sep, crdPath, fName)
         os.chdir(plPath)
-        #playlist open and show 
-        if item.find(str(fName), 0, 4) == -1: #tries to find out if playlist has  been used already, returns -1 if no duplicates
+        # playlist open and show
+        if item.find(str(fName), 0,
+                     4) == -1:  # tries to find out if playlist has  been used already, returns -1 if no duplicates
             try:
                 os.rename(str(item), fName + " " + str(item))
                 item = fName + " " + str(item)
             except:
-                print("Couldn't rename playlist " + str(item) + ". Aborting.")
-                input("Press Enter to quit...")
-                quit()
+                quitWithMessage("Couldn't rename playlist " + str(item) + ". Aborting.")
         playlistFile = open(item, "r")
         fileIndex = 0
         for line in playlistFile.readlines():
-            lineLower = line.lower() #convert to lower case to also find .MP3
-            if lineLower.find("file:") > -1: #only list lines that describe MP3 file path
-                fileIndex +=1
+            lineLower = line.lower()  # convert to lower case to also find .MP3
+            if lineLower.find(".mp3") > -1:  # only list lines that describe MP3 file path
+                fileIndex += 1
                 fName = playerFSnumbers(fileIndex, maxFileCnt)
                 tgtFileName = os.sep + fName + ".mp3"
-                line = line.strip() #strip removes New Line markers \n
-                if line.find("file:///") > - 1: #strip line of file marker within m3u
+                line = line.strip()  # strip removes New Line markers \n
+                if line.find("file:///") > - 1:  # strip line of file marker within m3u
                     line = line.split("file:///")[-1]
-                    #Also replace most commont HTML exclamations
-                    line = line.replace("%20", " ")
-                    line = line.replace("%21", "!")
-                    line = line.replace("%22", '"')
-                    line = line.replace("%23", "#")
-                    line = line.replace("%24", "$")
-                    line = line.replace("%25", "%")
-                    line = line.replace("%26", "&")
-                    line = line.replace("%27", "'")
-                    line = line.replace("%28", "(")
-                    line = line.replace("%29", ")")
-                    line = line.replace("%2A", "*")
-                    line = line.replace("%2B", "+")
-                    line = line.replace("%2C", ",")
-                    line = line.replace("%2D", "-")
-                    line = line.replace("%2E", ".")
-                    line = line.replace("%2F", "/")
-                    line = line.replace("%3A", ":")
-                    line = line.replace("%3B", ";")
-                    line = line.replace("%3C", "<")
-                    line = line.replace("%3D", "=")
-                    line = line.replace("%3E", ">")
-                    line = line.replace("%3F", "?")
-        
-                tgtFileName = fName + ".mp3" #new target file name
+                    line = replaceSpecialCharactersInPlaylist(line)
+                tgtFileName = fName + ".mp3"  # new target file name
                 try:
-                    print("Working...\n")
-                    shutil.copy2(line, os.path.join(os.sep, tgtFldrPath,  tgtFileName)) #copies & renames file from playlist to target folder
+                    shutil.copy2(line, os.path.join(os.sep, tgtFldrPath,
+                                                    tgtFileName))  # copies & renames file from playlist to tgt folder
                 except:
-                        print("Couldn't copy file\n" + str(line) + " to:\n" + str(tgtFldrPath) + "\nAborting.")
-                        quit()
-        print("Successfully copied %s files!" % (fileIndex,))
-    input("\n\nPress Return to quit")
+                    quitWithMessage("Couldn't copy file\n" + str(line) + " to:\n" + str(tgtFldrPath) + "\nAborting.")
+        quitWithMessage("Successfully copied %s files!" % fileIndex)
+else:
+    quitWithMessage("No playlists found in folder. Aborting.")