Switching between Python 2 and Python 3 environments#

You can easily maintain separate environments for Python 2 programs and Python 3 programs on the same computer, without worrying about the programs interacting with each other. Switching to an environment is called activating it.

Create a Python 2 environment named py2, install Python 2.7:
```
conda create --name py2 python=2.7
```
Create a new environment named py3, install Python 3.5:
```
conda create --name py3 python=3.5
```
Now you have two environments with which to work. You can install packages and run programs as desired in either one.
Activate and use the Python 2 environment.

Windows:
```
activate py2
```
macOS, Linux:
```
conda activate py2
```
Deactivate the Python 2 environment. Use your py2 environment to install packages and run programs as desired. When finished, deactivate the environment.

Windows:
```
deactivate
```
macOS, Linux:
```
conda deactivate
```
Activate and use the Python 3 environment.

Windows:
```
activate py3
```
macOS, Linux:
```
conda activate py3
```
Use the py3 environment to install and run programs as desired. When finished, deactivate the environment
Deactivate the Python 3 environment.

Windows:
```
deactivate
```
macOS, Linux:
```
conda deactivate
```