2.5 KiB
2.5 KiB
ADR-0001 Use the standard library instead of Pandas
Metadata
| Key | Value |
|---|---|
| ID | ADR-0001 |
| CrossReference | BC-001, SA-001, MIL-002 |
Version History
| Date | Status | Author | Reviewer | Change | Commit |
|---|---|---|---|---|---|
| 2026-10-13 | Accepted | Jens Tirsvad Nielsen | AI as stand-in for S01 | Initial version | 259d017 |
Allowed Status values: Proposed, Accepted, Rejected, Deprecated, Superseded by ADR-NNNN.
Context
The day 25 lecture reads the census with pandas.read_csv, filters rows by fur colour and builds a DataFrame for the export. The Business Case sets a success criterion of zero third-party runtime packages (BC-001, criterion 3), and stakeholder S03 wants a repository with no runtime dependencies (SA-001). Stakeholder S02 wants the function names of the assignment.
Options evaluated:
- Pandas — closest to the lecture; adds a large runtime dependency (with NumPy) that every visitor must install.
- Standard library — the
csvmodule to read and write andcollections.Counterto count; no runtime dependency, a few more lines than Pandas. - Pandas as an optional extra — two code paths for one result; more code to test and explain.
Decision
Use the standard library (csv and collections.Counter) for reading, counting and writing, and keep the lecture's step names (read_csv, count_by_fur_color, build_summary, write_csv) as public function names.
Consequences
Positive:
- The project has no runtime dependency;
pip install .installs only the package (BC-001 criterion 3). - Setup is the same on Windows PowerShell, Linux Debian and macOS, with no compiled wheels.
- The code is short enough to read in one sitting (S02).
Negative:
- The code differs from the lecture's Pandas calls, so a participant comparing line by line sees different statements.
- A later assignment that needs DataFrame features must introduce Pandas then.
Affected Artifacts
- BC-001 — meets success criterion 3 and mitigates the Pandas risk.
- SA-001 — resolves the conflict between S01's lecture and S03's expectation.
- MIL-002 — the tasks "Read the census file" to "Add the command line entry point" implement it.