01/24/2026: ok my python got messed up when i was trying to make some research lab code work and i feel like i need to fix it cuz its creating a lot of problems even in places where i didnt used to have problems like tdm

02/06/2026: cs471 assignment 1 required me to use python version 3.10 (but my computer system uses 3.11). the assignment told me to use conda to get the new version but ill use pyenv!

January 24, 2026

  1. show which python versions you have with pyenv
pyenv versions
  1. use pyenv to install python 3.11
pyenv install 3.11

^ installed python 3.11.13 (i used to have 3.11.11)

  1. shows which python version youre using
which python
  1. written record of which version you want to use on your system
nano .pyenv/version

^ update to 3.11.13 (it used to say 3.11.11)

i tried messing with this in my .zshrc file but its still cooked

before:

(in .zshrc)
## python cert
export SSL_CERT_FILE=$(python -m certifi)
(in terminal)
Last login: Fri Jan 23 23:08:55 on ttys001
/Users/julia7hk/.zshrc:124: command not found: python
➜  ~
➜  ~

after: (changed python to python3)

(in .zshrc)
## python cert
export SSL_CERT_FILE=$(python3 -m certifi)
(in terminal)
Last login: Fri Jan 23 23:07:19 on ttys000
/opt/homebrew/opt/python@3.14/bin/python3.14: No module named certifi
➜  ~
➜  ~

fixes the error in the section above:

/Users/julia7hk/.pyenv/versions/3.11.13/bin/python -m pip install certifi

final

➜  ~ pyenv versions
  system
* 3.11.13 (set by /Users/julia7hk/.pyenv/version)

⏺ Found it. In your ~/.zshrc, this line runs python -m certifi to set SSL_CERT_FILE:

export SSL_CERT_FILE=$(python -m certifi)

Since your current pyenv python resolves to 3.11.13 (which doesn’t exist yet), it produces a broken path.

Fix: temporarily unset it and install:p.

SSL_CERT_FILE="" pyenv install 3.11

This will use the system default certificates for the download. After that, you may want to update the line in ~/.zshrc to be more resilient — e.g., by using Homebrew’s cert bundle instead:

export SSL_CERT_FILE=$(brew —prefix)/etc/openssl@3/cert.pem

This avoids the circular dependency where the cert path depends on the very Python version you might be installing.

February 6, 2026

installing a different python version for cs471 (3.10 when i use 3.11)

use pyenv since i already have it installed and set up on my computer

➜  ~ pyenv versions
  system
* 3.11.13 (set by /Users/julia7hk/.pyenv/version)
in .zshrc:

## pyenv
export PYENV_ROOT="$HOME/.pyenv"
export PATH="$PYENV_ROOT/bin:$PATH"
eval "$(pyenv init -)"

install a new python version 3.10

pyenv install 3.10
➜  ~ pyenv versions
  system
  3.10.18
* 3.11.13 (set by /Users/julia7hk/.pyenv/version)

make python 3.10 the default python version in a specific folder

➜  cs471 pyenv versions
  system
  3.10.18
* 3.11.13 (set by /Users/julia7hk/.pyenv/version)
➜  cs471
➜  cs471
**➜  cs471 pyenv local 3.10.18**
➜  cs471
➜  cs471
➜  cs471 pyenv versions
  system
* 3.10.18 (set by /Users/julia7hk/_proj/00_purdue/cs471/.python-version)
  3.11.13
➜  cs471

initialize shell

python -m venv venv

run shell

source venv/bin/activate