How to install multiple packages in conda from a file without creating a new environment?

Question

I took these from yml file of packages that my current environment is missing. How do I just install these within my current environment?

channels:
  - defaults
dependencies:
  - appdirs=1.4.3=py36h28b3542_0
  - asn1crypto=0.24.0=py36_0
  - attrs=18.2.0=py36h28b3542_0
  - blas=1.0=mkl
  - cffi=1.11.5=py36h6174b99_1
  - constantly=15.1.0=py36h28b3542_0
  - cryptography=2.3.1=py36hdbc3d79_0
  - freetype=2.9.1=hb4e5f40_0
  - html5lib=1.0.1=py36_0
  - idna=2.7=py36_0
  - incremental=17.5.0=py36_0
  - intel-openmp=2019.0=118
  - libgfortran=3.0.1=h93005f0_2
  - libxml2=2.9.4=0
  - libxslt=1.1.29=hc208041_6
  - lxml=4.1.1=py36h6c891f4_0
  - mkl=2019.0=118
  - mkl_fft=1.0.6=py36hb8a8100_0
  - mkl_random=1.0.1=py36h5d10147_1
  - numpy=1.15.3=py36h6a91979_0
  - numpy-base=1.15.3=py36h8a80b8c_0
  - pyasn1=0.4.4=py36h28b3542_0
  - pyasn1-modules=0.2.2=py36_0
  - pycparser=2.19=py36_0
  - pyopenssl=18.0.0=py36_0
  - service_identity=17.0.0=py36h28b3542_0
  - twisted=17.5.0=py36_0
  - zope=1.0=py36_1
  - zope.interface=4.5.0=py36h1de35cc_0
  - pip:
    - absl-py==0.2.2
    - ete3==3.1.1
    - grpcio==1.12.1

Solution

Conda Env Update

If you have a YAML file, then the most efficacious way to apply it to a given env is with conda env update:

conda env update --file environment.yml

⚠️ Warning: The conda env commands don't prompt you to review and approve the transactions - it simply executes the changes. Be sure to carefully review the YAML file to ensure all of the changes are desired.

Conda Install

The format that Conda accepts for conda install --file is that which matches the output of conda list --export. It's not a YAML, but a simple text file with one package per line, similar to the one produced by pip freeze, except for the single equality sign ('=' rather than ==).

conda list --export

appdirs=1.4.3=py36h28b3542_0
asn1crypto=0.24.0=py36_0
...
zope=1.0=py36_1
zope.interface=4.5.0=py36h1de35cc_0

Note that the builds are not required, e.g., the following would also work and may actually be slightly more portable across architectures

appdirs=1.4.3
asn1crypto=0.24.0
...
zope=1.0
zope.interface=4.5.0

Unfortunately, conda install doesn't support PyPI packages; you'd have to install those separately via pip install in your activated env.