您必须在另一个线程中执行耗时的任务，例如在您的情况下是获取流和下载的任务。
import sys
import threading
from functools import cached_property
from PyQt5 import QtCore, QtWidgets
import pytube
class QPyTube(QtCore.QObject):
initialized = QtCore.pyqtSignal(bool, str)
download_started = QtCore.pyqtSignal()
download_progress_changed = QtCore.pyqtSignal(int)
download_finished = QtCore.pyqtSignal()
def __init__(self, url):
super().__init__()
self._url = url
self._yt = None
self._mutex = threading.Lock()
threading.Thread(target=self._init, daemon=True).start()
@property
def url(self):
return self._url
@cached_property
def resolutions(self):
return list()
def _init(self):
with self._mutex:
self.resolutions.clear()
try:
self._yt = pytube.YouTube(
self.url,
on_progress_callback=self._on_progress,
on_complete_callback=self._on_complete,
)
streams = self._yt.streams.filter(mime_type="video/mp4", progressive="True")
except Exception as e:
self.initialized.emit(False, str(e))
return
with self._mutex:
self.resolutions = [stream.resolution for stream in streams]
self.initialized.emit(True, "")
def download(self, resolution, directory):
threading.Thread(
target=self._download, args=(resolution, directory), daemon=True
).start()
def _download(self, resolution, directory):
stream = self._yt.streams.get_by_resolution(resolution)
self.download_started.emit()
stream.download(directory)
def _on_progress(self, stream, chunk, bytes_remaining):
self.download_progress_changed.emit(
100 * (stream.filesize - bytes_remaining) // stream.filesize
)
def _on_complete(self, stream, filepath):
self.download_finished.emit()
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super().__init__(parent)
self.le_url = QtWidgets.QLineEdit("http://youtube.com/watch?v=2lAe1cqCOXo")
self.lbl_error = QtWidgets.QLabel()
self.btn_search = QtWidgets.QPushButton("Search")
self.cmb_resolutions = QtWidgets.QComboBox()
self.le_directory = QtWidgets.QLineEdit("")
self.btn_download = QtWidgets.QPushButton("Download")
self.pgb_download = QtWidgets.QProgressBar()
central_widget = QtWidgets.QWidget()
self.setCentralWidget(central_widget)
lay = QtWidgets.QGridLayout(central_widget)
lay.addWidget(self.le_url, 0, 0)
lay.addWidget(self.btn_search, 0, 1)
lay.addWidget(self.cmb_resolutions, 1, 0)
lay.addWidget(self.le_directory, 1, 1)
lay.addWidget(self.btn_download, 1, 2)
lay.addWidget(self.pgb_download, 2, 0, 1, 3)
self.btn_download.setEnabled(False)
self._qpytube = None
self.btn_search.clicked.connect(self.handle_search_clicked)
self.btn_download.clicked.connect(self.handle_download_clicked)
def handle_search_clicked(self):
self.cmb_resolutions.clear()
self.btn_search.setEnabled(False)
self.btn_download.setEnabled(False)
self.lbl_error.clear()
self._qpytube = QPyTube(self.le_url.text())
self._qpytube.initialized.connect(self.handle_initialized)
self._qpytube.download_progress_changed.connect(self.pgb_download.setValue)
self._qpytube.download_started.connect(self.handle_download_started)
self._qpytube.download_finished.connect(self.handle_download_finished)
@QtCore.pyqtSlot(bool, str)
def handle_initialized(self, status, error=""):
if status:
self.cmb_resolutions.addItems(self._qpytube.resolutions)
self.btn_download.setEnabled(True)
else:
self.lbl_error.setText(error)
self.btn_search.setEnabled(True)
def handle_download_clicked(self):
self._qpytube.download(
self.cmb_resolutions.currentText(), self.le_directory.text()
)
self.btn_search.setEnabled(False)
self.btn_download.setEnabled(False)
self.le_directory.setEnabled(False)
def handle_download_started(self):
self.lbl_error.clear()
print("started")
def handle_download_finished(self):
self.pgb_download.setValue(100)
self.btn_search.setEnabled(True)
self.btn_download.setEnabled(True)
self.le_directory.setEnabled(True)
print("finished")
def main(args):
app = QtWidgets.QApplication(args)
w = MainWindow()
w.show()
app.exec_()
if __name__ == "__main__":
main(sys.argv)