Update python in Readme

README.md

@@ -59,13 +59,14 @@ To add a new class:
  - `-c`: class name (string) 
  - `-s`: class season/semester (fall, summer, spring) 
  - `-t`: target in docker file (string  – `base`, `r_lang` or `r_julia`) 
- - `-p`: python version (i.e 3.7 if ommited defaults to 3.10)
- - `-q`: wheter to install sqlite kernel (ommit the `-q` tag if sqlite is not required)
+ - `-p`: python version (i.e if ommited defaults to 3.9)
+ - `-q`: whether to install sqlite kernel (ommit the `-q` tag if sqlite is not required)
 
+The example below shows creating a class specifying the python version. Omitting the `-p` argument will use the default version (currently 3.9). The default python is configured in the `add_class.sh`.
 ```bash
 # e.g
 cd dev/
-./add_class.sh -c data1010 -t r_julia -s fall -p 3.7 -q
+./add_class.sh -c data1010 -t r_julia -s fall -p 3.9 -q
 ```
 
 To build the images locally:

dev/add_class.sh

@@ -2,7 +2,7 @@
 set -e
 
 #default version of Python to use
-PYTHON_VERSION=3.10
+PYTHON_VERSION=3.9
 
 usage () { echo "Usage:"
            echo "     -h – help"

docker-compose.yml

@@ -23,7 +23,7 @@ services:
       args: 
         CLASS: ${CLASS}
         SQLITE: ${SQLITE:-false}
-        PYTHON_VERSION: ${PYTHON_VERSION:-3.10}
+        PYTHON_VERSION: ${PYTHON_VERSION:-3.9}
     volumes:
       - ./requirements/out:/home/jovyan/tmp/out
     user: root