Fresh python 3.9.1 installation on macOS, shell is zsh

activated a venv with "python3 -m venv .venv"
activated with "source .venv/bin./activate"

"which python3" and "which pip3" both show my base installation

Please do not post screen captures. It makes it difficult for users with accessibility software and it makes it hard for people trying to help you to copy and paste exactly what you've tried.

I'm unable to duplicate your problem.

[~]$ ps
  PID TTY           TIME CMD
27521 ttys000    0:00.07 -zsh
[~]$ which python3
/Library/Frameworks/Python.framework/Versions/3.9/bin/python3
[~]$ python3 -m venv .venv
[~]$ source .venv/bin/activate
(.venv) [~]$ which python3
/Users/ericsmith/.venv/bin/python3

I'm also unable to replicate this. Where did you install Python from? Which version of zsh are you running?

zsh 5.8 (x86_64-apple-darwin20.0)
and
macOS Big Sur 11.2.1

This was the normal python dot org installation.

Are you sure there wasn't an existing virtual environment at .venv? By default, venv does not upgrade an existing environment. Try deleting the .venv directory first, assuming there is nothing in the environment you want to save. Otherwise you could try debugging the shell steps with the shell command:

set -x

and, if necessary, debugging the python environment with:

python3 -m test.pythoninfo

https://docs.python.org/3.9/library/venv.html

Just ran:

neelgore@Neels-MacBook-Pro Project 4:5 % rm -r .venv
neelgore@Neels-MacBook-Pro Project 4:5 % which python3  
/Library/Frameworks/Python.framework/Versions/3.9/bin/python3
neelgore@Neels-MacBook-Pro Project 4:5 % python3 -m venv .venv
neelgore@Neels-MacBook-Pro Project 4:5 % source .venv/bin/activate
(.venv) neelgore@Neels-MacBook-Pro Project 4:5 % which python3
/Library/Frameworks/Python.framework/Versions/3.9/bin/python3
(.venv) neelgore@Neels-MacBook-Pro Project 4:5 %

(sorry for double message)
update:

Just created a venv in Desktop and another in a directory in Documents and got the correct behavior both times. Seems like the issue is isolated to the certain directory?

Where did you install Python from?

Before you've activated the virtual env, please run "echo $PATH".

After you've activated the virtual env, can you run "ls -l .venv/bin" and "echo $PATH"?

It could be that the activate is failing for some reason in that directory or terminal session.  Try it in a new terminal session after entering "set -x" so you can see the expanded commands.

This is Python 3.9.1 from the normal python.org download.

Before venv activation, "echo $PATH" gives:

/Library/Frameworks/Python.framework/Versions/3.9/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Applications/VMware Fusion.app/Contents/Public

After activation, "ls -l .venv/bin" gives:

total 88
-rw-rw-r--  1 neelgore  staff  8834 Feb 14 14:51 Activate.ps1
-rw-rw-r--  1 neelgore  staff  1942 Feb 14 14:51 activate
-rw-rw-r--  1 neelgore  staff   891 Feb 14 14:51 activate.csh
-rw-rw-r--  1 neelgore  staff  2031 Feb 14 14:51 activate.fish
-rwxr-xr-x  1 neelgore  staff   327 Feb 14 14:51 easy_install
-rwxr-xr-x  1 neelgore  staff   327 Feb 14 14:51 easy_install-3.9
-rwxr-xr-x  1 neelgore  staff   318 Feb 14 14:51 pip
-rwxr-xr-x  1 neelgore  staff   318 Feb 14 14:51 pip3
-rwxr-xr-x  1 neelgore  staff   318 Feb 14 14:51 pip3.9
lrwxr-xr-x  1 neelgore  staff     7 Feb 14 14:51 python -> python3
lrwxr-xr-x  1 neelgore  staff    61 Feb 14 14:51 python3 -> /Library/Frameworks/Python.framework/Versions/3.9/bin/python3
lrwxr-xr-x  1 neelgore  staff     7 Feb 14 14:51 python3.9 -> python3

and "echo $PATH" gives:

/Users/neelgore/Documents/UC Irvine/Y1/Q2/ICS 32/Project 4:5/.venv/bin:/Library/Frameworks/Python.framework/Versions/3.9/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Applications/VMware Fusion.app/Contents/Public

Thanks. I’m guessing the space in the path is causing a problem.

What's the name of the current directory? Does it end with "Project 4:5"? It may be the colon in the directory name is interfering with the PATH parsing so that the shell thinks that the first two entries in your path after the venv activate are

/Users/neelgore/Documents/UC Irvine/Y1/Q2/ICS 32/Project 4
5/.venv/bin

instead of

"/Users/neelgore/Documents/UC Irvine/Y1/Q2/ICS 32/Project 4:5/.venv/bin"

being the first entry.

FWIW, it looks like spaces in directory names in macOS seem to be handled okay in both bash and zsh when working with venv's activate script. Colons do not and there doesn't appear to be a workaround other than not working in a directory with a colon in its name when you want to include that directory in your PATH.

Ah in hindsight I see why this was troublesome; the directory name was "Project 4/5", and zsh was displaying the / with a :. Renaming the directory to "Project 4_5" fixed the problem. Thanks everyone!