Implement UV for dependency lock

[i-am-sijia]

This PR implements UV as the new package and project manager for ActivitySim. #954

Changes to package and project management

• Updated pyproject.toml to work with UV [1]
• Implemented dependency lock with UV, added uv.lock for complete dependencies [1][2]
• Replaced various yaml files under "./conda-environments" with dependency groups in pyproject.toml [1]

Updates to GitHub Actions tests

• Updated the core tests to run on Windows VM instead of Linux. Since Windows is the primary platform that ActivitySim users use, it makes more sense to run tests on Windows [1][2][3]
• Updated the tests to use UV with dependency lock, instead of conda [1][2][3]

Updates to documentation

• Updated the release instructions [1]
• Updated the user doc and developer doc [1][2]

Other Fixes

• Pandas 2 got rid of the Int64Index dtype, which caused some existing tests to fail on Windows due to index type mismatch. We updated key state data tables' index type to ensure they are int64 across platforms and pandas versions. [1][2]

Update: This also solves Issue #958. Apparently index type int32 has caused bigger issues in full model runs that were not observed in our GitHub Actions tests. Our fix should address that too. See my response in: #958 (comment)

Consideration for future improvements

• Remove unused dependencies. We started off with retaining all the dependencies that were in the existing conda environment yaml files, and noticed that some packages that ActivitySim didn't require, such as orca, were still included in those yaml files. We removed some but definitely not all. It requires careful auditing and testing to remove all, which is out of scope for now.
• Remove version pins in pyproject.toml. With UV, we should not manually pin dependency versions in pyproject.toml with upper bounds (lower bounds are okay). If a pin is absolutely needed, there should be a GitHub issue associated with it and constantly being re-evaluated. Keep only direct dependencies in pyproject.toml
• Some, but not all, Sharrow tests are failing on Mac and Linux
• Benchmarking functions require code changes to remove conda. Or consider deprecating the functions.
• Remove conda from all jupyer notebooks in the repository

@josiekre

[Copilot]

Pull Request Overview

This PR introduces UV as the new package and project manager for ActivitySim by updating dependency constraints in pyproject.toml, replacing several conda environment YAML files, and adjusting related test and release workflows. Key changes include:

• Updating pyproject.toml to include dependency groups and a [tool.uv] section with stricter version constraints.
• Removing conda environment files in favor of managing dependencies with UV.
• Modifying code and GitHub Actions workflows to use uv-based commands (e.g. uv sync, uv run) and ensuring compatibility with Windows.

Reviewed Changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
pyproject.toml	Updated dependency constraints and added UV dependency groups and configuration
conda-environments/*.yml	Removed obsolete conda environment files
activitysim/core/input.py	Changed index type conversion to use np.int64 for clarity and consistency
activitysim/abm/models/mandatory_tour_frequency.py	Updated categorical creation for clarity
activitysim/abm/models/disaggregate_accessibility.py	Updated type conversion to np.int64 for consistency
HOW_TO_RELEASE.md	Revised release instructions to reflect uv-based dependency management
.python-version	Added to specify the Python version
.github/workflows/core_tests.yml	Updated workflows to install and use uv, and adjusted steps to run on Windows via uv-run

Comments suppressed due to low confidence (2)

HOW_TO_RELEASE.md:18

• Verify that all related developer and user documentation is updated to reflect the switch from conda to uv for dependency management.

    uv sync

.github/workflows/core_tests.yml:152

• Ensure that all workflow commands are compatible with PowerShell syntax, as switching from bash may lead to issues with commands originally written for bash.

        shell: pwsh

[jpn--]

Add a note here to remind users: if they already have uv installed from older projects and they they encounter errors later in the process, that they may need to update uv via uv self update or by using whichever package management tool is managing the uv tool. (e.g., I got "error: Failed to parse uv.lock ... missing field version" on my first attempt, which was resolved by updating uv)

[i-am-sijia]

Cool! Added the note. Thank you.

[jpn--]

default branch is now 'main' not 'master'

[i-am-sijia]

Good catch. Thanks.