Virtual environment using built_in venv
First of all python(IDLE) must be installed properly on our system.
To install python you can follow the steps from the given link
why do we use virtual environment?
-Python has a rich list of modules, and packages used for different applications.The purpose of virtual environment is to have space where we can install packages that are specific to a certain project
lets start working on our common prompt
Directly type cmd on search bar.
>cd desktop (Now I am on desktop)
>pip list (now you can see a list of packages here. These are my packages that i have already installed on my system installation of python)
Now lets create a new virtual environment-
>python -m venv full_dir_path/env_name(here venv module expects the environment name that you want to create)
>dir (to list out everything that are having on our desktop)
To activate our environment-
>project_name\Scripts\activate.bat
>where python(show the paths to current python comment and our environment directory)
if we want to install some packages
>pip install requests
>pip list
copy the path from the pip freeze and paste it on the new txt file and save it .
new is my text file name
If you want to delete virtual environment altogether you have to delete directory./s is to delete entire tree
>rmdir project_name /s
After deleted if we want to activate a new project then-
>mkdir xyza
>python -m venv xyza\venv
>xyza\venv\Scripts\activate.bat
lets use the requirements that have already been saved on txt file with the name “new.txt”.
>pip install -r new.txt
once installed,by typing “pip list” we will see the same installation that we made in last environment
>pip list
>cd xyza(project_name)
Create a new scripts on the desktop within venv, instead of txt i will write “.py” .
when we write “dir” within project_name,we will find “new_script.py” and “venv”( virtual Environment).under “venv” we put nothing
>dir
>xyza(project_name)
We should not commit our venv to source control ,when we find template ignored for python project then acually venv got ignored
>deactivate
>pip list
To delete newly created env
>rmdir venv /s (“/s” is to delete sub directories and type yes)
>y
For creating env that has access to those system packages-
>python -m venv venv — system-site-packages
To activate newly created env
>ven\Scripts\activate.bat
>pip list
lets create additional packages that are not available-
>pip install SQLAlchemy
Here,now you will find a newly created package
>pip list
If you want to see those that are being installed under this env then-
Note-in my list its showing same list as before because i have installed only those required packages
>pip list — local
lets see whether SQLAlchemy are installed in system packages?
>deactivate
Now we will find that SQLAlchemy is not installed on system packages for global version of python.
>pip list
