Pipenv: Staircase package downgraded after updating to Pandas 2.0

Question

I'm running pipenv 2023.3.20, pip 21.1.3. I updated pandas to version 2.0 from version 1.5.3. I did have to specify this version explicitly because updating as is wasn't actually updating pipfile.lock from the old version. Maybe this is a clue to the problem.

Now, my staircase package version has been downgraded from 2.5.0 to 2.0.0 and is causing errors in execution. When I try to update staircase pipenv update staircase==2.5.0

I get the following message:

Warning: Your dependencies could not be resolved. You likely have a mismatch in your sub-dependencies.
  You can use $ pipenv install --skip-lock to bypass this mechanism, then run $ pipenv graph to inspect the situation.
  Hint: try $ pipenv lock --pre if it is a pre-release dependency.
ERROR: ResolutionImpossible: for help visit https://pip.pypa.io/en/latest/topics/dependency-resolution/#dealing-with-dependency-conflicts

When I run pipenv graph, here is what I see under the staircase dependencies:

staircase==2.0.0
  - matplotlib [required: >=2, installed: 3.7.1]
    - contourpy [required: >=1.0.1, installed: 1.0.7]
      - numpy [required: >=1.16, installed: 1.23.5]
    - cycler [required: >=0.10, installed: 0.11.0]
    - fonttools [required: >=4.22.0, installed: 4.39.3]
    - importlib-resources [required: >=3.2.0, installed: 5.12.0]
      - zipp [required: >=3.1.0, installed: 3.15.0]
    - kiwisolver [required: >=1.0.1, installed: 1.4.4]
    - numpy [required: >=1.20, installed: 1.23.5]
    - packaging [required: >=20.0, installed: 23.0]
    - pillow [required: >=6.2.0, installed: 9.5.0]
    - pyparsing [required: >=2.3.1, installed: 3.0.9]
    - python-dateutil [required: >=2.7, installed: 2.8.2]
      - six [required: >=1.5, installed: 1.16.0]

Answer 1

There is an upper bound on the pandas dependency in staircase. Such is the default when packaging with Poetry. Whether these upper bounds are good practice or not is a hotly debated topic.

I am the maintainer so I'll fix up a compatible release this weekend if not before.

I must have published 2.0 without the upper bound on pandas which is why it is reverting.

Feel free to drop an issue on the Github repo for staircase if you have any troubles in the future!

• Riley