Using conda install within a python script

You can use conda.cli.main. For example, this installs numpy:

import conda.cli

conda.cli.main('conda', 'install',  '-y', 'numpy')

Use the -y argument to avoid interactive questions:

-y, --yes Do not ask for confirmation.

I was looking at the latest Conda Python API and noticed that there are actually only 2 public modules with “very long-term stability”:

1. conda.cli.python_api
2. conda.api

For your question, I would work with the first:

NOTE: run_command() below will always add a -y/--yes option (i.e. it will not ask for confirmation)

import conda.cli.python_api as Conda
import sys

###################################################################################################
# The below is roughly equivalent to:
#   conda install -y 'args-go-here' 'no-whitespace-splitting-occurs' 'square-brackets-optional'

(stdout_str, stderr_str, return_code_int) = Conda.run_command(
    Conda.Commands.INSTALL, # alternatively, you can just say "install"
                            # ...it's probably safer long-term to use the Commands class though
                            # Commands include:
                            #  CLEAN,CONFIG,CREATE,INFO,INSTALL,HELP,LIST,REMOVE,SEARCH,UPDATE,RUN
    [ 'args-go-here', 'no-whitespace-splitting-occurs', 'square-brackets-optional' ],
    use_exception_handler=True,  # Defaults to False, use that if you want to handle your own exceptions
    stdout=sys.stdout, # Defaults to being returned as a str (stdout_str)
    stderr=sys.stderr, # Also defaults to being returned as str (stderr_str)
    search_path=Conda.SEARCH_PATH  # this is the default; adding only for illustrative purposes
)
###################################################################################################

---

The nice thing about using the above is that it solves a problem that occurs (mentioned in the comments above) when using conda.cli.main():

...conda tried to interpret the comand line arguments instead of the arguments of conda.cli.main(), so using conda.cli.main() like this might not work for some things.

---

The other question in the comments above was:

How [to install a package] when the channel is not the default?

import conda.cli.python_api as Conda
import sys

###################################################################################################
# Either:
#   conda install -y -c <CHANNEL> <PACKAGE>
# Or (>= conda 4.6)
#   conda install -y <CHANNEL>::<PACKAGE>

(stdout_str, stderr_str, return_code_int) = Conda.run_command(
    Conda.Commands.INSTALL,
    '-c', '<CHANNEL>',
    '<PACKAGE>'
    use_exception_handler=True, stdout=sys.stdout, stderr=sys.stderr
)
###################################################################################################