运行SpeechRecognition代码时PySide2.QtGui无QApplication属性报错

问题背景 #

使用speech_recognition库的音频识别代码：

import speech_recognition as sr

def recognize():
    r = sr.Recognizer()
    
    with sr.AudioFile("test.wav") as source:
        audio = r.record(source)
    
    print(r.recognize_google(audio))
    
recognize()

首次运行提示缺少PySide2，安装后出现以下错误：

Failed to enable GUI event loop integration for 'qt'
Traceback (most recent call last):
  File "c:\program files\microsoft visual studio\2022\enterprise\common7\ide\extensions\microsoft\python\core\debugpy\_vendored\pydevd\pydev_ipython\matplotlibtools.py", line 30, in do_enable_gui
    enable_gui(guiname)
  File "c:\program files\microsoft visual studio\2022\enterprise\common7\ide\extensions\microsoft\python\core\debugpy\_vendored\pydevd\pydev_ipython\inputhook.py", line 540, in enable_gui
    return gui_hook(app)
  File "c:\program files\microsoft visual studio\2022\enterprise\common7\ide\extensions\microsoft\python\core\debugpy\_vendored\pydevd\pydev_ipython\inputhook.py", line 180, in enable_qt
    self.enable_qt4(app)
  File "c:\program files\microsoft visual studio\2022\enterprise\common7\ide\extensions\microsoft\python\core\debugpy\_vendored\pydevd\pydev_ipython\inputhook.py", line 205, in enable_qt4
    app, inputhook_qt4 = create_inputhook_qt4(self, app)
  File "c:\program files\microsoft visual studio\2022\enterprise\common7\ide\extensions\microsoft\python\core\debugpy\_vendored\pydevd\pydev_ipython\inputhookqt4.py", line 84, in create_inputhook_qt4
    app = QtGui.QApplication([" "])
AttributeError: module 'PySide2.QtGui' has no attribute 'QApplication'
Backend QtAgg is interactive backend. Turning interactive mode on.

解决方案 #

1. 更换matplotlib后端（最简单有效） #

错误源于调试器集成的matplotlib Qt后端适配问题，直接指定非Qt后端即可：
在代码开头添加以下两行：

import matplotlib
matplotlib.use('TkAgg') # 或使用'Agg'（非交互式，适合无GUI环境）

修改后的完整代码：

import matplotlib
matplotlib.use('TkAgg')
import speech_recognition as sr

def recognize():
    r = sr.Recognizer()
    
    with sr.AudioFile("test.wav") as source:
        audio = r.record(source)
    
    print(r.recognize_google(audio))
    
recognize()

2. 用PyQt5替代PySide2 #

卸载当前PySide2，安装PyQt5：

pip uninstall PySide2 -y
pip install PyQt5

PyQt5的模块结构与旧版适配更好，能避开该属性错误。

3. 命令行直接运行（绕开IDE调试器问题） #

该错误仅在VS调试模式下触发，直接用命令行执行代码即可正常运行：

python your_script_name.py

4. 降级PySide2到兼容版本 #

安装5.12.x版本的PySide2，该版本中QApplication仍保留在QtGui模块的兼容导入：

pip install PySide2==5.12.0

内容的提问来源于stack exchange，提问作者BaRiboD