microtrade-fwf 0.2.9

Turn zipped fixed-width (FWF) trade microdata into Hive-partitioned Parquet datasets.

microtrade

Turn monthly drops of zipped fixed-width (FWF) trade microdata into Hive-partitioned Parquet datasets, one per trade type.

microtrade streams each raw zip directly from its archive (no extraction, bounded memory), slices columns according to a versioned YAML spec, and writes year=YYYY/month=MM/part-0.parquet atomically under a per-type dataset root. Monthly runs reprocess all months YTD of the current year; prior years are frozen.

Raw filenames don't have to follow any fixed convention — each committed spec carries its own filename_pattern regex, so workbooks from different upstream generations (SHEET002_202404N.TXT.zip, XYZ12345_Im202404.zip, etc.) can coexist as long as each pattern captures year and month (and optionally flag) from the filename.

Three trade types are supported, each with its own distinct schema:

• imports
• exports_us
• exports_nonus

Requirements

• Python 3.12+
• uv for environment and dependency management

Install

uv sync

This resolves and installs runtime + dev dependencies into .venv/ based on pyproject.toml and uv.lock.

Usage

Write a project config (microtrade.yaml)

The authoritative schema lives in an Excel workbook, but the wiring between workbooks, trade types, period windows, and raw filenames lives in a project config. microtrade import-spec reads it to produce each YAML spec; the ingest pipeline never touches this file.

# microtrade.yaml
workbooks:
  XYZ12345_Record_Layout.xls:
    workbook_id: XYZ12345         # optional; defaults to filename prefix
    effective_from: 2020-01
    effective_to: 2023-12         # optional; absent = open-ended
    sheets:
      Imports:
        trade_type: imports       # optional; defaults to positional (sheet index -> TRADE_TYPES)
        filename_pattern: '^XYZ12345_Im(?P<year>\d{4})(?P<month>\d{2})\.zip$'
        routing_column: year_month  # per-row Date column; used to partition output
        cast:
          year_month: Date          # workbook ships as Char; promote to Date
        parse:
          year_month: yyyymm_to_date

  Schedule_Record_Layout_2024.xlsx:
    effective_from: 2024-01
    sheets:
      Imports:
        trade_type: imports
        filename_pattern: '^IMP_(?P<year>\d{4})(?P<month>\d{2})(?P<flag>[NC])\.TXT\.zip$'
        routing_column: period
        # Upstream renamed `business_number` -> `business_number_9_digit`;
        # keep the stable name in the combined dataset.
        rename:
          business_number_9_digit: business_number
      ExportsUS:
        trade_type: exports_us
        filename_pattern: '^EXUS_(?P<year>\d{4})(?P<month>\d{2})(?P<flag>[NC])\.TXT\.zip$'
        routing_column: period
      ExportsNonUS:
        trade_type: exports_nonus
        filename_pattern: '^EXNONUS_(?P<year>\d{4})(?P<month>\d{2})(?P<flag>[NC])\.TXT\.zip$'
        routing_column: period

Required regex groups: year (4 digits) and month (2 digits). Optional: flag — when upstream publishes both N and C copies of the same period, N wins at discovery time.

routing_column (defaults to period) names the per-row Date column that the pipeline uses to bucket rows into year=YYYY/month=MM partitions. It must resolve to a Date column in the final spec — either because the workbook already declares it that way, or because cast + parse promote it. Upstream schemas name this column differently (period, year_month, ref_month, …) so the field is per-sheet rather than a hardcoded convention.

Match the value against the logical (post-rename) column name. If you rename foo_physical → bar_logical, set routing_column: bar_logical. Columns with no rename match on their physical name.

rename (optional, per sheet) maps a workbook's physical column name (the Description cell) to the logical name that shows up in the combined dataset. Each Spec stores both, ingest slices FWF bytes under physical_name and emits the parquet column under logical_name so consumers see one stable column even as upstream drifts.

cast (optional, per sheet) overrides the workbook's declared dtype per column. Upstream FWF specs routinely label numeric or date fields as Char; use cast to promote them at import time, e.g. cast: {value_usd: Int64, year_month: Date}. Allowed targets: Utf8, Int64, Float64, Date.

parse (optional, per sheet) overrides the parser for a Date column. The default is yyyymmdd_to_date; set parse: {year_month: yyyymm_to_date} for YYYYMM fields. Only meaningful for columns whose final dtype is Date.

computed (optional, per sheet) builds new parquet columns from other columns at ingest time. Keyed by the output column's name; values declare a named operation (kind) and its sources. First available operation:

• concat_to_date: sources: [period_date_col, day_col] → Date column combining a YYYYMM Date and a day-of-month (Int64 or Utf8 — '02' parses the same as 2) into a full YYYYMMDD date. Row-level failures (e.g. Feb 30, unparseable day) go to the quality log like any other parse error.
• concat_text: sources: [col_a, col_b, ...] → Utf8 column that joins N Utf8 sources with separator (default " "), skipping null or blank/whitespace-only sources and collapsing every run of whitespace (including tabs/newlines) in the joined result to a single space. A row with every source blank emits null. Override the separator with separator: "-" (or any string).

computed:
  full_name:
    kind: concat_text
    sources: [first_name, last_name]
    separator: " "          # optional; default is a single space

computed:
  entry_date:
    kind: concat_to_date
    sources: [period, day_of_month]

drop (optional, per sheet) omits named columns from the parquet output. Runs after cast/rename/computed, so a dropped column can still feed a computed column and disappear afterward:

drop: [day_of_month]   # used by `entry_date`, then dropped from the output

A worked example lives at examples/microtrade.yaml, paired with examples/microdata-layout.xls.

Import the schema workbook (once per schema version)

Each sheet's field table is autodetected by looking for a row containing Position, Description, Length, and Type; rows with Description = Blank are FWF padding and are skipped.

Convert a workbook to versioned YAML specs:

uv run microtrade import-spec XYZ12345_Record_Layout.xls

The importer looks up the workbook in microtrade.yaml (override location with --config PATH) and writes one YAML per trade type under src/microtrade/specs/<trade_type>/v<effective_from>.yaml. Each file is a self-contained runtime contract — review and commit. Re-run with --force to replace an existing version. When a new workbook lands, add a second entry to the config with its own period window; the pipeline picks the appropriate spec per period automatically, and a column-level diff against the previous version is printed.

Ingest raw monthly zips

uv run microtrade ingest \
    --input  /path/to/raw_zips   \
    --output /path/to/datasets

Discovery walks every committed spec's filename_pattern and routes each file to the spec that matches; files that match nothing are silently ignored, and files that match more than one spec raise (ambiguous config — tighten the regexes). microtrade.yaml is not consulted at ingest time; everything the pipeline needs is already baked into the YAML specs.

Defaults: year-to-date of the current calendar year, all three trade types, zstd-compressed Parquet. Common flags:

Flag	Default	Purpose
--type imports	all	Repeat for multiple; limits processing
--year 2024	unset	Process a single year (disables YTD logic)
--month 4	unset	Combine with --year for one-shot re-ingest
--all	off	Process every year present under --input
--chunk-rows 250000	250000	Rows per Parquet row group / memory batch
--compression zstd	zstd	Parquet compression codec
--encoding cp1252	cp1252	Text encoding of the inner FWF (pass --encoding utf-8 for UTF-8 data)

Per-partition outcomes are logged as JSON lines under <output>/_manifests/<trade_type>/<run_id>.jsonl, and a one-line summary is printed at the end. The exit code is non-zero if any partition failed; other partitions in the same run still complete.

Output layout

output/
  imports/
    year=2024/month=01/part-0.parquet
    year=2024/month=02/part-0.parquet
    ...
  exports_us/
    year=2024/month=01/part-0.parquet
    ...
  exports_nonus/
    ...
  _manifests/
    imports/<run_id>.jsonl
    exports_us/<run_id>.jsonl
    exports_nonus/<run_id>.jsonl

Partition columns (year, month) are encoded in the directory path only, not duplicated inside each Parquet file. Read with any Hive-aware scanner:

import polars as pl

df = pl.scan_parquet("output/imports", hive_partitioning=True).collect()

Or with DuckDB:

SELECT * FROM read_parquet('output/imports/**/*.parquet', hive_partitioning=1);

Ops: cron-driven runs

microtrade ops run is a thin planner on top of microtrade ingest for unattended environments (k8s CronJob, typically). It hashes workbooks + raw zips, compares them against per-file JSON manifests on disk, and re-runs only the parts that actually changed. Use it when you want the "every N minutes, do the minimum work" loop; use microtrade ingest directly for one-shot manual reprocessing.

Two stages per run:

1. Stage 1 — import-spec. For each workbook under workbooks_dir whose content hash (or the paired microtrade.yaml hash) differs from its last manifest, re-run microtrade import-spec into specs_dir.
2. Stage 2 — ingest. Group raw zips under raw_dir by (trade_type, year) via each sheet's filename_pattern. If any raw in a year is dirty (new, changed, or the paired microtrade.yaml changed), re-run microtrade.pipeline.run for that whole year (since each raw is a YTD snapshot, the year is the reprocessing unit — not the month).

Paths + directories live in a separate config.yaml loaded by microtrade.ops.settings (env overrides: MT_RAW_DIR=/data/raw, etc.):

# config.yaml
microtrade_yaml:    /app/microtrade.yaml
workbooks_dir:      /data/workbooks
raw_dir:            /data/raw
specs_dir:          /data/specs
processed_dir:      /data/processed
spec_manifests_dir: /data/manifests/specs
raw_manifests_dir:  /data/manifests/raw
upstream_raw_dir:     /mnt/upstream/raw     # where the provider drops files
raw_remote_dir:       /mnt/remote/raw       # our durable archive
processed_remote_dir: /mnt/remote/processed # remote Parquet destination
manifests_remote_dir: /mnt/remote/manifests # shared dirty-check state

Run:

uv run microtrade ops run --config config.yaml

Exit code is 0 on clean completion (including "nothing to do") and non-zero if any year or workbook failed; the failed items simply have no manifest update, so the next cronjob run replans them automatically. loguru handles logging (no custom sinks).

The manifests under spec_manifests_dir / raw_manifests_dir are the only stateful artifact the ops layer owns. Wire the pull_manifests and push_manifests transport hooks (below) to a shared backend and multiple operators — different pods, different clusters, different people — converge on the same "what's already clean" view without needing to share the rest of the PV.

A transport seam wraps the ordering contract:

pull_manifests → mirror → pull → stage 1 → stage 2 (push per year) → push_manifests

pull_manifests fetches the shared dirty-check state before planning so a pod that doesn't have the previous run's PV still skips already- done work. push_manifests publishes the updated state at the end of the run (even if some years failed — partial progress is worth sharing). Path routing is owned by the library and driven by config.yaml; only the per-file transfer primitive is injectable:

from microtrade.ops.runner import run
from microtrade.ops.settings import load_settings

# Default: shutil.copy2 (local disk / mounted PV). No kwarg needed.
sys.exit(run(load_settings(Path("config.yaml"))))

# Or swap in your own one-file-at-a-time primitive (kubectl cp,
# S3 put_object, etc.). It MUST preserve mtime or the skip-if-
# unchanged check misfires and every file re-copies next run.
sys.exit(run(
    load_settings(Path("config.yaml")),
    copy_file=my_kubectl_cp_wrapper,
))

Point your k8s CronJob's command at this wrapper instead of microtrade ops run when you need a custom copy primitive. See examples/ops_demo.py for a runnable walkthrough.

See CLAUDE.md for the full list of invariants (dirty-check logic, manifest schemas, k8s deployment guidance, what the ops layer explicitly does not do).

Architecture

config.load_config(yaml)       -> ProjectConfig (import-spec only)
excel_spec.read_workbook       -> Spec per sheet, with filename_pattern baked in
discover.scan(input_dir)       -> list[RawInput] (by matching each committed pattern)
schema.resolve(specs, period)  -> Spec whose [effective_from, effective_to] contains period
ingest.iter_record_batches     -> pyarrow.RecordBatch stream (bounded memory)
write.PartitionWriter          -> year=/month=/part-0.parquet.tmp, atomic rename
pipeline.run                   -> orchestrates the above + JSONL manifest
ops.planner + ops.runner       -> cron-driven dirty-check + dispatch on top of pipeline.run

Key invariants:

• Excel + microtrade.yaml are the upstream source of truth; committed YAML under src/microtrade/specs/ is the runtime contract. The pipeline never reads Excel, and consults the project config only via import-spec.
• Each partition write is idempotent: re-running YTD cleanly replaces the current year's partitions, leaving prior years untouched.
• The zip is decompressed on the fly via zipfile.ZipFile.open(); the raw FWF is never extracted to disk and never fully materialized in memory.
• Per-partition failures are recorded in the manifest but do not abort the run
  • one bad month will not block the rest.
• validate-specs flags overlapping or gapped [effective_from, effective_to] windows so silent ambiguities in schema.resolve don't reach production.

Development

uv run pytest                                     # full suite with coverage
uv run pytest tests/test_pipeline.py::test_name   # single test
uv run ruff format                                # auto-format
uv run ruff check                                 # lint
uv run mypy src                                   # strict type check
uv run pre-commit run --all-files                 # all pre-commit hooks

Tests build synthetic Excel workbooks, YAML specs, and FWF zips on the fly in tests/_helpers.py rather than checking in binary fixtures, so the exercised code paths match the real production workflow end-to-end.

Status

The pipeline is feature-complete: scaffolding, project config, Excel → YAML, discover + ingest + write, the orchestrated CLI subcommands (ingest, import-spec, inspect, validate-specs), and the cron-driven ops layer (microtrade ops run) are all landed and covered. Reference YAML specs ship under src/microtrade/specs/ but predate the filename_pattern field (tracked in issue #16) — replace them by writing a microtrade.yaml and running microtrade import-spec against the real schema workbook. A new workbook goes into the config as a second entry with its own effective_from/effective_to; the pipeline picks the right spec per period automatically. Run microtrade validate-specs after importing to catch dtype conflicts and window overlaps/gaps between versions.

License

MIT (see LICENSE).