wind@wind-ThinkPad-X250:~/Downloads/PyQt5_gpl-5.12.2$ python3 -m pip install PyQt5
Collecting PyQt5
 Downloading https://files.pythonhosted.org/packages/6a/f4/6a63aafcee3efd2b156dc835d9c85ca99b24e80f8af89b6da5c46054fe43/PyQt5-5.12.2-5.12.3-cp35.cp36.cp37.cp38-abi3-manylinux1_x86_64.whl (61.5MB)
  100% |████████████████████████████████| 61.5MB 18kB/s 
Collecting PyQt5_sip<13,>=4.19.14 (from PyQt5)
 Downloading https://files.pythonhosted.org/packages/08/19/ef6b97cfdbb8f9312d71388384f572706e40bf88f07fffb0fc64846b4a36/PyQt5_sip-4.19.17-cp35-cp35m-manylinux1_x86_64.whl (67kB)
  100% |████████████████████████████████| 71kB 107kB/s 
Installing collected packages: PyQt5-sip, PyQt5
Successfully installed PyQt5-5.12.2 PyQt5-sip-4.19.17
You are using pip version 8.1.1, however version 19.1.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
wind@wind-ThinkPad-X250:~/Downloads/PyQt5_gpl-5.12.2$ 

>>> import sys
>>> sys.modules.keys()
dict_keys(['problem_report', '_bz2', 'email.feedparser', 'email.mime', 'base64', 'select', 'tarfile', '__future__', '_compat_pickle', 'importlib.util', 'mpl_toolkits', 'json.scanner', 'signal', 'json', 're', 'subprocess', 'ipaddress', 'configparser', '_functools', 'bz2', 'uu', 'pyexpat', 'copyreg', '__main__', 'selectors', 'apt.package', 'PyQt5', 'xml', 'pyexpat.errors', '_json', '_thread', 'email.message', 'apt.cdrom', 'calendar', 'importlib.abc', 'textwrap', 'random', 'email.mime.text', 'email._encoded_words', 'email._parseaddr', 'shutil', 'atexit', 'sre_parse', '_frozen_importlib_external', 'importlib.machinery', '_compression', 'zlib', 'copy', 'fcntl', '_weakref', 'sitecustomize', 'collections.abc', 'apport_python_hook', 'email.header', 'email.errors', '_io', '_operator', 'email.encoders', '_string', 'contextlib', '_frozen_importlib', '_pickle', 'apt.cache', 'token', '_signal', '_collections_abc', 'email._policybase', 'apt.progress', 'encodings.utf_8', 'genericpath', '_hashlib', 'heapq', '_socket', '_stat', 'site', 'sysconfig', 'xml.dom.minicompat', 'socket', '_struct', 'string', 'email.charset', 'importlib', 'pyexpat.model', 'gzip', 'codecs', '_warnings', 'apport.packaging_impl', 'threading', 'encodings', 'builtins', 'enum', 'binascii', 'http', 'itertools', 'operator', '_ssl', 'xml.parsers.expat', '_datetime', 'glob', '_locale', '_random', 'apport.fileutils', 'xml.dom.NodeFilter', '_posixsubprocess', 'abc', 'urllib.error', 'datetime', 'sre_constants', 'json.encoder', 'encodings.aliases', 'reprlib', '_weakrefset', 'json.decoder', 'importlib._bootstrap_external', 'sre_compile', 'email.mime.base', 'email.parser', 'math', 'keyword', 'encodings.latin_1', 'linecache', '_heapq', 'urllib', 'apport', 'tokenize', 'importlib._bootstrap', 'urllib.response', 'xml.parsers.expat.errors', 'apport.report', 'apport.packaging', 'posixpath', 'gettext', 'xml.dom.xmlbuilder', 'xml.dom', 'pwd', 'os', '_sysconfigdata_m', '_sitebuiltins', 'errno', 'xml.parsers.expat.model', 'os.path', '_sysconfigdata', '_sre', 'email.mime.multipart', 'collections', 'apt.progress.base', 'traceback', 'apt', 'io', 'weakref', 'urllib.request', 'hashlib', 'email.iterators', 'quopri', 'http.client', 'zipimport', '_imp', 'sys', 'rlcompleter', '_bootlocale', 'locale', 'urllib.parse', 'fnmatch', 'tempfile', 'xml.dom.domreg', '_codecs', 'bisect', 'email.utils', 'email.mime.nonmultipart', '_bisect', 'stat', 'warnings', 'ssl', 'functools', 'email', 'grp', '_lzma', 'email.quoprimime', 'struct', 'apt.progress.text', 'time', 'xml.parsers', 'email.base64mime', 'apt_pkg', 'pickle', 'imp', 'types', 'xml.dom.minidom', 'lzma', 'marshal', '_collections', 'readline', 'posix'])
>>> 

wind@wind-ThinkPad-X250:~$ sudo python3 -m pip uninstall PyQt5
[sudo] password for wind: 
WARNING: The directory '/home/wind/.cache/pip/http' or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
Uninstalling PyQt5-5.12.2:
 Would remove:
  /home/wind/.local/bin/pylupdate5
  /home/wind/.local/bin/pyrcc5
  /home/wind/.local/bin/pyuic5
  /home/wind/.local/lib/python3.5/site-packages/PyQt5-5.12.2.dist-info/*
  /home/wind/.local/lib/python3.5/site-packages/PyQt5/*
 Would not remove (might be manually added):
  /home/wind/.local/lib/python3.5/site-packages/PyQt5/sip.so
Proceed (y/n)? y
 Successfully uninstalled PyQt5-5.12.2
wind@wind-ThinkPad-X250:~$ 

#!/bin/env python3 
# -*- coding: utf-8 -*- 
 
import sys
from PyQt5.QtWidgets import QApplication, QWidget  #導入相應的包
 
if __name__ == '__main__':
 
   app = QApplication(sys.argv)     #創建QApplication對象是必須，管理整個>程序，參數可有可無，有的話可接收命令行參數
 
   w = QWidget()            #創建窗體對象，
   w.resize( 250, 150 )         #設置窗體大小
   w.move( 100, 300 )          #設置在屏幕上的顯示位置
   w.setWindowTitle( 'Simple' )     #設置窗口標題
   w.show()               #窗口顯示
 
   sys.exit( app.exec_() )