filelens 0.1.1

CLI to inspect and normalize messy data files into clean tables

filelens

Turn messy files into clean tables in one command.

filelens is a CLI that helps you understand and clean messy data files.

Ever opened a file where:

• headers start on row 6
• metadata is mixed with data
• columns are inconsistent

filelens lets you:

• inspect structure and issues
• infer a schema
• convert to a clean table (Parquet)

No config. No guessing. Deterministic output.

Quick start

filelens inspect file.csv
filelens convert file.csv --out file.parquet

Install (pip)

Build and install locally:

pip install .

pip install . builds from source and requires Rust/Cargo on your machine.

Build a distributable wheel:

maturin build -b bin --release -o dist
pip install dist/filelens-*.whl

Example

Before

Metadata + mixed rows + unclear structure:

Metadata: Device=LabX
Date: 2024-01-01

Sample ID,Value,Unit
S1,0.45,mg/mL
S2,0.50,mg/mL

Inspect:

filelens inspect sample.csv

Output:

Detected:
- header row: 4
- metadata rows: 1-3
- columns: 3

Warnings:
- none

One command

filelens convert sample.csv --out sample.parquet

What it does:

• detects structure
• skips metadata
• infers schema
• writes sample.parquet

After

Clean table:

sample_id | value | unit
S1        | 0.45  | mg/mL
S2        | 0.50  | mg/mL

Supported inputs

Supports common messy data formats used in analytics and healthcare.

• Excel / CSV (messy tabular files): .xlsx, .xlsm, .xls, .csv, .tsv, .psv, .txt
• JSON (nested data): .json, .ndjson
• XML (including cXML / CDA / NAACCR): .xml, .cxml, .xcml
• HL7 (basic extraction): .hl7, .msg
• Compressed text variants: .gz wrappers for supported text formats

Design

• deterministic (no AI guessing)
• no config required
• optimized for messy real-world files

When to use filelens

• You opened a file and do not understand its structure
• Your Excel export has metadata rows and broken headers
• You need to convert XML/JSON into a table quickly
• You want clean input for dbt or a data warehouse

Command reference

Inspect:

filelens inspect data/file.xlsx
filelens inspect data/order.cxml
filelens inspect data/patient-example.json
filelens inspect data/oru_r01.msg
filelens inspect data/clinical.xml
filelens inspect data/patient-example.ttl
filelens inspect data/patient-example.ttl.html

Schema:

filelens schema data/file.xlsx
filelens schema data/patient-example.json --parser fhir

Convert:

filelens convert data/file.xlsx --out data/file.parquet
filelens convert data/order.cxml --out data/order.parquet
filelens convert data/nested_lab_result.json --out data/nested_lab_result.parquet
filelens convert data/oru_r01.msg --out data/oru_r01.parquet
filelens convert data/patient-example.ttl --out data/patient-example.ttl.parquet

Optional parser override:

filelens inspect data/file.xml --parser cda
filelens inspect data/file.json --parser json
filelens inspect data/file.json --parser fhir
filelens inspect data/file.msg --parser hl7
filelens inspect data/file.ttl --parser rdf

If running from source, use ./target/release/filelens instead of filelens.

Works with dbt

filelens outputs Parquet files that can be loaded into warehouses and modeled with dbt.

Use it in this order:

1. Convert files to parquet.
2. Load parquet into Postgres raw.filelens_lines.
3. Run dbt models.
4. Query typed marts.

Setup env vars:

export PGHOST=localhost
export PGPORT=5432
export PGUSER=...
export PGPASSWORD=...
export PGDATABASE=postgres
export DBT_PROFILES_DIR=dbt

One-command local pipeline (public examples only):

scripts/auto_load_and_run_dbt.sh --parquet-glob "$PWD/output/public/**/*.parquet" --full-refresh

What this command does:

• loads parquet into raw.filelens_lines
• syncs raw into raw_procurement and raw_clinical
• runs staging models
• runs marts (including typed marts)
• runs tests
• prints row counts and next query hints

Which tables to query:

• analytics_marts.fct_procurement_lines for procurement analytics
• analytics_marts.fct_fhir_resources for FHIR analytics
• analytics_marts.fct_naaccr_cases for NAACCR analytics
• analytics_marts.fct_record_attributes for generic key/value search across all extracted attributes

analytics_registry.idx_filelens_records is a cross-format registry/index table (lineage + canonical fields). It is not the primary end-user analytics table.

Why keep raw -> internal -> marts:

• raw: ingestion/debug layer (what got loaded)
• analytics_internal: normalization layer (map parser-specific columns into stable canonical fields)
• marts: consumption layer (deduped and typed tables for analysts/apps)

Example consumer queries:

select * from analytics_marts.fct_procurement_lines limit 20;
select * from analytics_marts.fct_fhir_resources limit 20;
select * from analytics_marts.fct_naaccr_cases limit 20;
select * from analytics_marts.fct_record_attributes limit 20;

Trace NAACCR attributes back to original source ids:

select
  source_file,
  record_key,
  attribute_scope,
  attribute_source_id,
  attribute_name,
  attribute_value
from analytics_marts.fct_record_attributes
where source_kind = 'naaccr'
  and attribute_source_id in ('grade', 'patientidnumber', 'tumorrecordnumber')
limit 20;

Examples

See examples/ for real sample inputs:

• procurement (cXML / xCML)
• healthcare (FHIR, HL7, CDA, NAACCR)
• RDF/Turtle (.ttl, .ttl.html)
• messy CSV/TSV/PSV/TXT

Build

cargo build --release

Binary path:

./target/release/filelens

Release (GitHub Actions)

Tag-based release:

git tag v0.1.0
git push origin v0.1.0

What happens on tag push (v*):

• builds platform wheels (Linux, macOS Intel/ARM, Windows)
• builds source distribution on Linux
• creates a GitHub Release and uploads dist/* artifacts

Optional PyPI publish:

• configure PyPI Trusted Publisher for this repo (recommended)
• on tag push, distributions are published to PyPI via GitHub OIDC
• or run the Release workflow manually with publish_pypi=true

PyPI Trusted Publisher settings:

1. PyPI project -> Manage -> Publishing -> Add a new publisher -> GitHub.
2. Set:
   • Owner: <your-github-owner>
   • Repository name: filelens
   • Workflow name: release.yml
   • Environment name: pypi
3. Save. No API token secret is required.

Workflow

What this workflow does:

• builds the filelens binary
• converts only examples/public files into parquet under output/public
• loads only output/public/**/*.parquet into Postgres raw tables
• runs dbt staging + marts with --full-refresh (and tests)
• does not include non-public example paths unless you change the command

Why --full-refresh in this demo workflow:

• it rebuilds marts from scratch so the demo is deterministic after parser/model changes
• it avoids stale incremental state while iterating locally
• for recurring production loads, omit --full-refresh and use incremental dbt runs

cargo build --release
scripts/convert_inputs.sh --input-dir examples/public --output-dir output/public

export PGHOST=localhost
export PGPORT=5432
export PGUSER=...
export PGPASSWORD=...
export PGDATABASE=postgres
export DBT_PROFILES_DIR=dbt

scripts/auto_load_and_run_dbt.sh --parquet-glob "$PWD/output/public/**/*.parquet" --full-refresh

scripts/convert_inputs.sh is non-strict by default (skips failures and continues). Add --strict to fail on first conversion error.

Advanced formats

• RDF/Turtle (.ttl, .rdf) — experimental support
• HTML pages containing RDF/Turtle <pre> blocks (for example *.ttl.html)

Why not pandas?

pandas can read files, but it does not:

• detect likely header/metadata layout
• explain quality issues up front
• normalize mixed file families with one deterministic CLI pass

filelens is focused on that first cleanup step before your pipeline.