How to fix “ImportError: unable to find Qt5Core.dll on PATH” after pyinstaller bundled the python application

Question

Can\'t run QT based GUI application bundled by pyinstaller, the console output shows it is due to an import error:

ImportError: unable to find

Answer 1

I comment all content of file site-packages\PyQt5\__init__.py and install again. It works.

I use python3.5 with PyInstaller=3.5 and PyQt5=5.13.0.The packaged exe is working on my computer, but does not work on others. The error message is:

 File "anaconda3\lib\site-packages\PyInstaller\loader\pyimod03_importers.py", line 627, in exec_module
  File "site-packages\PyQt5\__init__.py", line 41, in 
  File "site-packages\PyQt5\__init__.py", line 33, in find_qt
ImportError: unable to find Qt5Core.dll on PATH

So I see site-packages\PyQt5\__init__.py(5.13.0) is:

def find_qt():
    import os

    path = os.environ['PATH']

    dll_dir = os.path.dirname(__file__) + '\\Qt\\bin'
    if os.path.isfile(dll_dir + '\\Qt5Core.dll'):
        path = dll_dir + ';' + path
        os.environ['PATH'] = path
    else:
        for dll_dir in path.split(';'):
            if os.path.isfile(dll_dir + '\\Qt5Core.dll'):
                break
        else:
            raise ImportError("unable to find Qt5Core.dll on PATH")

    try:
        os.add_dll_directory(dll_dir)
    except AttributeError:
        pass


find_qt()
del find_qt

I think PyQt5 can't find the PATH in the other computer although Qt5Core.dll already exists in the project directly. So I commented out the file and now it works.