bandcamp album ripper (python3)

import os, sys, re, json, urllib.request, urllib.parse, urllib.error, threading
from functools import partial
from PyQt4 import QtCore, QtGui
from win32api import GetSystemMetrics

Dimensions = [512, 512]
XY = [GetSystemMetrics (i)/2-(Dimensions[i]/2) for i in range(2)] #create window in center of screen
XY += Dimensions

class Window(QtGui.QWidget):

    def __init__(self):
        super(Window, self).__init__()
        self.initUI()

    def initUI(self):
        self.setGeometry(*XY)
        self.setFixedSize(*Dimensions)
        self.setWindowTitle("Bandcamp Ripper")
        self.show()

        urlInput = QtGui.QLineEdit(self)
        urlInput.show()

        scanInitialize = QtGui.QPushButton(self)
        scanInitialize.setText("Fetch")

        scanInitialize.show()

        songListDisplay = QtGui.QTreeWidget(self)
        songListDisplay.setHeaderLabels(["Name", "Url", "Download status"])
        songListDisplay.show()

        urlInput.setPlaceholderText("Enter bandcamp album URL")

        toplayout = QtGui.QGridLayout(self)
        toplayout.addWidget(scanInitialize, 0, 0)
        toplayout.addWidget(urlInput,       0, 1)

        mainGroup = QtGui.QGroupBox(self)
        mainGroup.setTitle("URL")
        #mainGroup.setMinimumWidth(512)
        mainGroup.setMinimumHeight(30)
        mainGroup.setLayout(toplayout)
        mainGroup.show()

        ArtistLabel = QtGui.QLabel(self)
        ArtistLabel.setText("Artist")
        FoundArtistLabel = QtGui.QLabel(self)
        FoundArtistLabel.setText("...")

        AlbumLabel = QtGui.QLabel(self)
        AlbumLabel.setText("Album Art")
        FoundAlbumLabel = QtGui.QLabel(self)
        FoundAlbumLabel.setText("...")

        NameLabel = QtGui.QLabel(self)
        NameLabel.setText("Album Name")
        FoundNameLabel = QtGui.QLabel(self)
        FoundNameLabel.setText("...")

        SongLabel = QtGui.QLabel(self)
        SongLabel.setText("Songs")
        FoundSongLabel = QtGui.QLabel(self)
        FoundSongLabel.setText("...")

        objectsFound = QtGui.QGridLayout(self)
        objectsFound.addWidget(ArtistLabel,      0, 0)
        objectsFound.addWidget(FoundArtistLabel, 0, 1)
        objectsFound.addWidget(AlbumLabel,       1, 0)
        objectsFound.addWidget(FoundAlbumLabel,  1, 1)
        objectsFound.addWidget(NameLabel,        2, 0)
        objectsFound.addWidget(FoundNameLabel,   2, 1)
        objectsFound.addWidget(SongLabel,        3, 0)
        objectsFound.addWidget(FoundSongLabel,   3, 1)

        statusBox = QtGui.QGroupBox(self)
        statusBox.setTitle("Album scan status")
        #statusBox.setMinimumWidth(512)
        statusBox.setMinimumHeight(30)
        statusBox.setLayout(objectsFound)
        statusBox.show()

        downloadInitialize = QtGui.QPushButton(self)
        downloadInitialize.setText("Begin Download")
        downloadInitialize.setDisabled(True)

        MAINlayout = QtGui.QGridLayout(self)
        MAINlayout.addWidget(mainGroup,          0, 0)
        MAINlayout.addWidget(statusBox,          1, 0)
        MAINlayout.addWidget(downloadInitialize, 2, 0)
        MAINlayout.addWidget(songListDisplay,    3, 0)

        self.setLayout(MAINlayout)

        def confirm():
            if not re.match("^https?:\/{2}.+\.?[bandcamp]?\.com\/album\/.+$", urlInput.text()): #Test if iput is valid URL
                QtGui.QMessageBox.warning(self, "Error", "Invalid Url\nValid example: http://artist.bandcamp.com/album/albumname")
            else:
                url = str(urlInput.text())
                data = urllib.request.urlopen(url).read()
                toFind = {
                    "Artist": {
                        "Found": False,
                        "Collected": None,
                        "Pattern": 'BandData.+?{.+?name: "(.+?)".+?};',
                        "Namespace": "artistName",
                        "iPath": FoundArtistLabel
                    },
                    "Art": {
                        "Found": False,
                        "Collected": None,
                        "Pattern": 'TralbumData.+?{.+?artFullsizeUrl: "(.+?)".+?};',
                        "Namespace": "artData",
                        "iPath": FoundAlbumLabel
                    },
                    "Album": {
                        "Found": False,
                        "Collected": None,
                        "Pattern": 'EmbedData.+?{.+?album_title: "(.+?)".+?};',
                        "Namespace": "albumName",
                        "iPath": FoundNameLabel
                    },
                    "Songs": {
                        "Found": False,
                        "Collected": None,
                        "Pattern": 'trackinfo.+?(\[.+?\])',
                        "Namespace": "songsData",
                        "iPath": FoundSongLabel
                    }
                }

                # I probably shouldn't put this here, but...
                def downloadInit():
                    directory = toFind["Album"]["Collected"]+"/"
                    if not os.path.exists(directory):
                        os.mkdir(directory)
                    urllib.request.urlretrieve(toFind["Art"]["Collected"], directory+"Album"+os.path.splitext(toFind["Art"]["Collected"])[1])
                    # ^^ download cover art
                    def threadedDL():
                        root = songListDisplay.invisibleRootItem()
                        def subThread(child_):
                            rc = root.child(child_)
                            rc.setText(2, "Downloading...")
                            fileName = "{0} - {1}.mp3".format(toFind["Artist"]["Collected"], rc.text(0))
                            urllib.request.urlretrieve("http:"+str(rc.text(1)), directory+fileName)
                            rc.setText(2, "Done!")
                        for i in range(root.childCount()):
                            sub = threading.Thread(target=partial(subThread, i))
                            #sub.daemon = True
                            sub.start()
                    t = threading.Thread(target=threadedDL)
                    t.daemon = True
                    t.start()

                for subject in toFind:
                    try:
                        regex_data = re.findall(toFind[subject]["Pattern"], str(data), re.DOTALL)
                        if len(regex_data) == 1:
                            toFind[subject]["Collected"] = regex_data[0]
                        else:
                            toFind[subject]["Collected"] = list(reversed(sorted(regex_data,key=len)))[0]
                        toFind[subject]["Found"] = True
                        toFind[subject]["iPath"].setText("Found!")
                    except Exception as e:
                        QtGui.QMessageBox.warning(self, "Error", e)
                try:
                    toFind["Songs"]["Collected"]=[(str(i["title"]), str(i["file"]['mp3-128'])) for i in json.loads(toFind["Songs"]["Collected"])]
                except Exception as e:
                    QtGui.QMessageBox.warning(self, "Error", e)
                # ^^^^ Turn "songs" list into tuples formatted like (name, url)
                #scanInitializees into tree widget below...
                for i in toFind["Songs"]["Collected"]:
                    sitem = QtGui.QTreeWidgetItem(list(i) + ["Pending"])
                    songListDisplay.addTopLevelItem(sitem)
                downloadInitialize.setDisabled(False)
                downloadInitialize.clicked.connect(downloadInit)
        scanInitialize.clicked.connect(confirm)


def main():
    ab = QtGui.QApplication(sys.argv)
    ex = Window()
    sys.exit(ab.exec_())

if __name__ == '__main__':
    main()