Question: Hi I'm a beginner of python, I don't remember when and how I installed python3.8 on my Macbook air, only knew the installed path: % which python /usr/bin/python % which python3 /usr/local/bin/python3  The pip command cannot not be found but pip3 is ok. Today I want to install virtaulenv: % sudo -H pip3 install virtualenv WARNING: Ignoring invalid distribution - (/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages) Successfully installed virtualenv-20.6.0  I can use "pip3 show virtualenv" to know the info: % pip3 show virtualenv Name: virtualenv Version: 20.6.0 Summary: Virtual Python Environment builder Home-page: https://virtualenv.pypa.io/ Author: Bernat Gabor Author-email: gaborjbernat@gmail.com License: MIT Location: /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages Requires: six, platformdirs, backports.entry-points-selectable, distlib, filelock Required-by:  But when I use "virtualenv" I got command not found message then I "pip3 uninstall" it. I searched for this and got a tip to use "easy_install" to install virtualenv. After installed I can execute the command, but got some error message: % virtualenv Traceback (most recent call last): File "/usr/local/bin/virtualenv", line 6, in <module> from pkg_resources import load_entry_point File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources/__init__.py", line 3241, in <module> @_call_aside File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources/__init__.py", line 3225, in _call_aside f(*args, **kwargs) File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources/__init__.py", line 3254, in _initialize_master_working_set working_set = WorkingSet._build_master() File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources/__init__.py", line 583, in _build_master ws.require(__requires__) File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources/__init__.py", line 900, in require needed = self.resolve(parse_requirements(requirements)) File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources/__init__.py", line 786, in resolve raise DistributionNotFound(req, requirers) pkg_resources.DistributionNotFound: The 'importlib-resources>=1.0' distribution was not found and is required by virtualenv  It seems doesn't work and I try the "sudo pip3 uninstall virtualenv" to uninstall it successfully, but it seems not really be removed: % which virtualenv /usr/local/bin/virtualenv  I have no idea about this, could you help me? I just want to run virtualenv normally and create flask project ... PS. I can "sudo pip3 install flask" and "pip3 show flask" but still cannot run flask cammand (command not found), what should I do? Thanks a lot!

Answer: try being explicit in the version of python you are using and install using -m pip instead python3 -m pip install virtualenv python3 -m virtualenv venv # create a new venv in ./venv source ./venv/bin/activate # activate your new venv  often times the pip/pip3 just isnt pointing at the same python version you think you are using... by using this technique you are sure to be using the correct python and pip