* Migrate backend dataframe layer from pandas to polars
Replace pandas with polars across the backend, dropping both pandas and its
pyarrow parquet engine from the dependency set. numpy stays (the grading
percentile math is unchanged).
- climate.py: parquet IO, source→frame mappings, cache read/topup on polars.
New _normalize_read casts the cached `date` column to pl.Date (older files
were written by pandas as datetime64[ns]); frames now unify missing values as
null so the grading boundary drops them consistently across sources.
- grading.py: keep the numpy percentile core; swap the frame→numpy bridge to
.to_numpy()/.drop_nulls(), day-of-year/year to polars dt expressions, and the
per-row loop to iter_rows(named=True).
- views.py: filter/anti-join/concat replace boolean-mask, isin and pd.concat;
scalar dates are stdlib datetime.date; a local _months_before helper replaces
DateOffset(months=) for the calendar-range default.
- app.py, migrate.py: request-date parsing uses datetime.date, removing pandas
from the endpoint and migrate layers entirely.
- The date column is pl.Date end to end, eliminating the pandas normalize() calls
and comparing cleanly against stdlib dates.
Payloads are unchanged: calendar, day, grade and forecast responses are
byte-for-byte identical to the pandas implementation on the same cached record.
Tests ported to polars fixtures, with added coverage for the combined feels-like
fallback, calendar month-offset (month-end/leap), and the concat/dedup
"fresher source wins" rule.
* Port notify.py to polars after merging dev's account system
Merge origin/dev (accounts + notification subscriptions) and carry the pandas→
polars migration into the newly added notify.py, which the merge brought in still
using pandas — with pandas removed from requirements this broke its import.
- notify.py: _candidate_rows filters/sorts the recent bundle with polars
expressions and returns iter_rows dicts; date scalars are datetime.date;
history/recent emptiness via is_empty().
- test_notify.py: synthetic history/rows built with polars + datetime.
- Fix the mobile width blow-out: the distribution grid item (.cmp-dist-row) had no
min-width:0, so each row expanded to the 9–10-column connected bar chart's
min-content and widened the whole page (zoom-out, clipped filter sheet). Add
grid-template-columns: minmax(0,1fr) + min-width:0 so the strip scrolls inside its
own .ct-strip, and tighten .ct-col to 34px on phones.
- Add a Load/Refresh button inside the compare filter sheet's date-range block, wired
to the same refresh()/isDirty(); editing the range on mobile no longer needs the
sheet closed. The existing button stays in the controls (loads added places).
- Default date range on both pages is now January six years back → the present. On
the calendar this is an explicit chunked range (the months=24 path is server-capped
at ~2yr).
- Names now include country: reverse_geocode appends it to the place label; revgeo
cache key gets a v2 prefix and PAYLOAD_VER bumps to p2 so labels/payloads
repopulate.
- Location names read as a hierarchy: compact chips show just the lead segment (full
name in the title/aria), and each ranked card shows the lead segment bold over a
muted "city · region · country" line.
Frontend + a small backend name/cache change; no schema migration.
The derived store's key/token formats existed in three places — each
endpoint, api_cell's slice assembly, and migrate.py — where any drift
would silently split the cache (endpoints missing rows the bundle wrote,
migrate materializing rows nobody reads). They are now defined once in
views.py (grade_key/calendar_key/day_key/forecast_key, history_token/
recent_token/day_token) and consumed everywhere, with a pinning test so
a format change is always deliberate.
The four data endpoints shared two copy-pasted sequences, now helpers:
- _fetch_history: history (+ optional recent bundle) fetch with upstream
failures mapped to clean HTTP errors and an empty record to 404.
- _cached_response: If-None-Match 304 / token-valid store replay /
build + persist + serve, with calendar's dont-persist-placeless rule
as an explicit flag.
Each endpoint is now its audit run + identity + a build callback (~10
lines); api_day's hourly-token special case moved into day_token. New
tests: identity format pins, rate-limit 503 parametrized across all five
data routes, prefetch=1 never touching upstream (cold 204, warm
history-only slices), and calendar's placeless-payload retry behavior.
app.py had grown three co-resident strata: HTTP/caching plumbing, payload
assembly, and search policy. This moves the payload layer — the four
build_* functions, cal_span clamping, hist_end, PAYLOAD_VER, NullRun and
their helpers — into a new views.py with no web dependencies (pure moves,
public names). app.py keeps routing, ETag/derived-store plumbing, and
page serving; migrate.py imports views instead of reaching into app's
privates.
That import previously constructed the whole FastAPI app and — because
places.start_loading() ran at import time — kicked off a background
GeoNames download from an offline batch script. The index load now hangs
off the app's lifespan hook, so it fires when a server starts, not when
the module is imported (tests, migrate).
New tests: cal_span clamping (months-back default, record bounds, 2-year
cap, inversion), builder shapes (grade window ordering, day obs from the
recent bundle, forecast future-only), a regression test that build_day
degrades to climatology when the recent fetch fails, and a subprocess
layering guard that importing views/migrate pulls in neither FastAPI nor
the app module and starts no index download.
