To start using the new virtual environment from the command line, pass the following argument inside the folder that holds the virtual environment. This will run the activate batch file, and will start the virtual environment:

C:\PythonGeospatial3>cartoenv\Scripts\activate

Once the virtual environment is activated, the name of the environment will appear before the folder name, indicating that the commands are being run inside the environment and any changes that are performed (such as installing modules) will not affect the main Python installation:

(cartoenv) C:\PythonGeospatial3>

In a Linux environment, the command source {environment}/bin/activate is used instead. When programming in Linux, the commands in the terminal would look like this:

silas@ubuntu16:~$ mkdir carto
silas@ubuntu16:~$ cd carto/
silas@ubuntu16:~/carto$ virtualenv cartoenv
New python executable in /home/silas/carto/cartoenv/bin/python
Installing setuptools, pip, wheel...done.
silas@ubuntu16:~/carto$ source cartoenv/bin/activate
(cartoenv) silas@ubuntu16:~/carto$

In either OS, to deactivate the virtual environment, pass the deactivate command. This will end the virtual session:

C:\PythonGeospatial3>cartoenv\Scripts\activate

(cartoenv) C:\PythonGeospatial3>deactivate
C:\PythonGeospatial3>