为什么终端中没有运行pip3命令？

Question

当我运行pip3 --version或pip3 --help或与pip3相关的任何命令时，在终端上显示以下错误。

 Traceback (most recent call last):
  File "/usr/bin/pip3", line 9, in <module>
    from pip import main
  File "/usr/lib/python3/dist-packages/pip/__init__.py", line 29, in <module>
    from pip.utils import get_installed_distributions, get_prog
  File "/usr/lib/python3/dist-packages/pip/utils/__init__.py", line 27, in <module>
    from pip._vendor import pkg_resources
ImportError: cannot import name 'pkg_resources'
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 63, in apport_excepthook
    from apport.fileutils import likely_packaged, get_recent_crashes
  File "/usr/lib/python3/dist-packages/apport/__init__.py", line 5, in <module>
    from apport.report import Report
  File "/usr/lib/python3/dist-packages/apport/report.py", line 15, in <module>
    import xml.dom, xml.dom.minidom
ModuleNotFoundError: No module named 'xml.dom'

Original exception was:
Traceback (most recent call last):
  File "/usr/bin/pip3", line 9, in <module>
    from pip import main
  File "/usr/lib/python3/dist-packages/pip/__init__.py", line 29, in <module>
    from pip.utils import get_installed_distributions, get_prog
  File "/usr/lib/python3/dist-packages/pip/utils/__init__.py", line 27, in <module>
    from pip._vendor import pkg_resources
ImportError: cannot import name 'pkg_resources'

请帮助我。