如何将一个 conda 环境“克隆”到根环境中？

There are options to copy dependency names/urls/versions to files.

Recommendation

Normally it is safer to work from a new environment rather than changing root. However, consider backing up your existing environments before attempting changes. Verify the desired outcome by testing these commands in a demo environment. To backup your root env for example:

λ conda activate root
λ conda env export > environment_root.yml
λ conda list --explicit > spec_file_root.txt

Options

Option 1 - YAML file

Within the second environment (e.g. myenv), export names⁺ to a yaml file:

λ activate myenv
λ conda env export > environment.yml

then update the first environment⁺ (e.g. root) with the yaml file:

λ conda env update --name root --file environment.yml

Option 2 - Cloning an environment

Use the --clone flag to clone environments (see @DevC's post):

λ conda create --name myclone --clone root

This basically creates a direct copy of an environment.

Option 3 - Spec file

Make a spec-file⁺⁺ to append dependencies from an env (see @Ormetrom):

λ activate myenv
λ conda list --explicit > spec_file.txt
λ conda install --name root --file spec_file.txt

Alternatively, replicate a new environment (recommended):

λ conda create --name myenv2 --file spec_file.txt

See Also

• conda env for more details on the env sub-commands.
• Anaconada Navigator desktop program for a more graphical experience.
• Docs on updated commands. With older conda versions use activate (Windows) and source activate (Linux/Mac OS). Newer versions of conda can use conda activate (this may require some setup with your shell configuration via conda init).
• Discussion on keeping conda env

Extras

There appears to be an undocumented conda run option to help execute commands in specific environments.

# New command
λ conda run --name myenv conda list --explicit > spec_file.txt

The latter command is effective at running commands in environments without the activation/deactivation steps. See the equivalent command below:

# Equivalent
λ activate myenv
λ conda list --explicit > spec_file.txt
λ deactivate

Note, this is likely an experimental feature, so this may not be appropriate in production until official adoption into the public API.

^{+Conda docs have changed since the original post; links updated. ++Spec-files only work with environments created on the same OS. Unlike the first two options, spec-files only capture links to conda dependencies; pip dependencies are not included.}

To make a copy of your root environment (named base), you can use following command; worked for me with Anaconda3-5.0.1:

conda create --name <env_name> --clone base

you can list all the packages installed in conda environment with following command

conda list -n <env_name>

When setting up a new environment and I need the packages from the base environment in my new one (which is often the case) I am building in the prompt a identical conda environment by using a spec-file.txt with:

conda list --explicit > spec-file.txt

The spec-file includes the packages of for example the base environment.

Then using the prompt I install the the packages into the new environment:

conda create --name myenv --file spec-file.txt

The packages from base are then available in the new environment.

The whole process is describe in the doc: https://docs.conda.io/projects/conda/en/latest/user-guide/tasks/manage-environments.html#building-identical-conda-environments

I also ran into the trouble of cloning an environment onto another machine and wanted to provide an answer. The key issue I had was addressing errors when the current environment contains development packages which cannot be obtained directly from conda install or pip install. For these cases I highly recommend conda-pack (see this answer):

pip install conda-pack

or,

conda install conda-pack

then back up the environment, to use the current environment just omit the my_env name,

# Pack environment my_env into my_env.tar.gz
$ conda pack -n my_env


# Pack environment my_env into out_name.tar.gz
$ conda pack -n my_env -o out_name.tar.gz


# Pack environment located at an explicit path into my_env.tar.gz
$ conda pack -p /explicit/path/to/my_env

and restoring,

# Unpack environment into directory `my_env`
$ mkdir -p my_env
$ tar -xzf my_env.tar.gz -C my_env


# Use Python without activating or fixing the prefixes. Most Python
# libraries will work fine, but things that require prefix cleanups
# will fail.
$ ./my_env/bin/python


# Activate the environment. This adds `my_env/bin` to your path
$ source my_env/bin/activate


# Run Python from in the environment
(my_env) $ python


# Cleanup prefixes from in the active environment.
# Note that this command can also be run without activating the environment
# as long as some version of Python is already installed on the machine.
(my_env) $ conda-unpack