When building conda packages using conda-build and my code uses pure python libraries, what do I need to put in build/host/run in the meta.yaml file?

Question

Let's say I have a python package that uses pandas, numpy and matplotlib. If I look at their meta.yaml files, I see a lot of dependencies in the requirements section. E.g. compilers like make. Do I need to name all those dependencies from the build and host section also in my own meta.yaml package or does it suffice if I just write:

Requirements:
Host: 
- python 3.8
Build: 
- python 3.8
Run:
- pandas
- numpy
- matplotlib

Answer 1

You can just specify your package's python dependencies. Here's an example from conda-forge.

Here's a made-up example:

package:
  name: foobar
  version: 0.1

source:
  git_url: https://github.com/greenfish/foobar
  git_tag: v0.1

build:
  number: 0
  noarch: python
  script: {{ PYTHON }} -m pip install . --no-deps -vv

requirements:
  host:
    - python
    - pip
  run:
    - python
    - pandas >=1.0
    - numpy

test:
  imports:
    - foobar

about:
  home: http://greenfish-foobar.org
  license: BSD-3-Clause
  license_file: LICENSE.txt
  summary: This package is for all your foobar needs