How do I prevent Conda from activating the base environment by default?

There're 3 ways to achieve this after conda 4.6. (The last method has the highest priority.)

1. Use sub-command conda config to change the setting.

   conda config --set auto_activate_base false
   

2. In fact, the former conda config sub-command is changing configuration file .condarc. We can modify .condarc directly. Add following content into .condarc under your home directory,

   # auto_activate_base (bool)
   #   Automatically activate the base environment during shell
   #   initialization. for `conda init`
   auto_activate_base: false
   

3. Set environment variable CONDA_AUTO_ACTIVATE_BASE in the shell's init file. (.bashrc for bash, .zshrc for zsh)

   export CONDA_AUTO_ACTIVATE_BASE=false
   

   To convert from the condarc file-based configuration parameter name to the environment variable parameter name, make the name all uppercase and prepend CONDA_. For example, conda’s always_yes configuration parameter can be specified using a CONDA_ALWAYS_YES environment variable.

   The environment settings take precedence over corresponding settings in .condarc file.

References

• The Conda Configuration Engine for Power Users
• Using the .condarc conda configuration file
• conda config --describe
• Conda 4.6 Release

I have conda 4.6 with a similar block of code that was added by conda. In my case, there's a conda configuration setting to disable the automatic base activation:

conda config --set auto_activate_base false

The first time you run it, it'll create a .condarc in your home directory with that setting to override the default.

This wouldn't de-clutter your .bash_profile but it's a cleaner solution without manual editing that section that conda manages.