for this link,i had tried the methods in it,but dont work for me;

https://answers.ros.org/question/257331/python-module-empy-missing-tutorials/

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i tried the following 6 command ,dont work

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sudo pip2 uninstall em

The directory '/home/lzw/.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 em-0.4.0:


  /usr/local/lib/python2.7/dist-packages/em-0.4.0.dist-info/DESCRIPTION.rst
  /usr/local/lib/python2.7/dist-packages/em-0.4.0.dist-info/INSTALLER
  /usr/local/lib/python2.7/dist-packages/em-0.4.0.dist-info/METADATA
  /usr/local/lib/python2.7/dist-packages/em-0.4.0.dist-info/RECORD 
  /usr/local/lib/python2.7/dist-packages/em-0.4.0.dist-info/WHEEL
  /usr/local/lib/python2.7/dist-packages/em-0.4.0.dist-info/entry_points.txt
  /usr/local/lib/python2.7/dist-packages/em-0.4.0.dist-info/metadata.json
  /usr/local/lib/python2.7/dist-packages/em-0.4.0.dist-info/top_level.txt
  /usr/local/lib/python2.7/dist-packages/em/__init__.py
  /usr/local/lib/python2.7/dist-packages/em/__init__.pyc
  /usr/local/lib/python2.7/dist-packages/em/locale/em.pot
  /usr/local/lib/python2.7/dist-packages/em/locale/fr/LC_MESSAGES/em.mo
  /usr/local/lib/python2.7/dist-packages/em/locale/ru/LC_MESSAGES/em.mo
  /usr/local/lib/python2.7/dist-packages/em/locale/uk/LC_MESSAGES/em.mo
  /usr/local/lib/python2.7/dist-packages/em/tests/__init__.py
  /usr/local/lib/python2.7/dist-packages/em/tests/__init__.pyc
  /usr/local/lib/python2.7/dist-packages/em/tests/basic.py
  /usr/local/lib/python2.7/dist-packages/em/tests/basic.pyc

Proceed (y/n)? y
  Successfully uninstalled em-0.4.0

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sudo pip2 install empy

Requirement already satisfied: empy in /usr/lib/python2.7/dist-packages

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sudo pip uninstall em

WARNING: Skipping em as it is not installed.

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sudo pip install empty

Successfully installed Werkzeug-1.0.1 click-7.1.2 empty-0.4.4 flask-1.1.2 itsdangerous-1.1.0

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sudo apt-get install python-empy

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sudo apt-get install python3-empy

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