fabrictools 0.4.4

User-friendly PySpark helpers for Microsoft Fabric Lakehouses and Warehouses

fabrictools

User-friendly PySpark helpers for Microsoft Fabric — read, write, and merge Lakehouses and Warehouses with a single function call.

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Features

• Auto-resolved paths — pass a Lakehouse or Warehouse name, no ABFS URL configuration required
• Auto-detected SparkSession — uses SparkSession.builder.getOrCreate(), works seamlessly inside Fabric notebooks
• Auto-detected format on read — tries Delta → Parquet → CSV automatically
• Auto-corrected Lakehouse read paths — supports bare or partial paths (e.g. customers, dbo/customers) with fallback to Tables/dbo/... then Files/...
• Auto-corrected Lakehouse write paths — partial paths are normalized to Tables/dbo/... while explicit Files/... paths are preserved
• Delta merge (upsert) — one-liner upsert into any Lakehouse Delta table
• Generic data cleaning — standard cleaning with one helper function
• Silver metadata enrichment — add ingestion/source metadata + year/month/day partitions
• Data quality scan — detect nulls, blank strings, duplicates, and naming collisions
• Bulk lakehouse cleaning — iterate all tables and copy cleaned outputs to another Lakehouse
• Source → Prepared pipeline — profile schema, resolve semantics, transform, optimize, and publish BI assets
• Dimension generators — build dimension_date, dimension_country, and dimension_city with Lakehouse/Warehouse writes
• Built-in logging — every operation logs its resolved path, detected format, and row/column count

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Requirements

• Microsoft Fabric Spark runtime (provides notebookutils, pyspark, and delta-spark)
• Python >= 3.9

Local development: install the spark extras to get PySpark and delta-spark. notebookutils is only available inside Fabric — functions that resolve paths will raise a clear ValueError outside Fabric.

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Installation

# Inside a Fabric notebook or pipeline
pip install fabrictools

# Local development (includes PySpark + delta-spark)
pip install "fabrictools[spark]"

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Quick start

import fabrictools as ft

Read a Lakehouse dataset

# Auto-detects Delta → Parquet → CSV
df = ft.read_lakehouse("BronzeLakehouse", "sales/2024")

# Also accepts partial paths:
# - "customers"      -> tries Tables/dbo/customers then Files/customers
# - "dbo/customers"  -> tries Tables/dbo/customers

Write to a Lakehouse

ft.write_lakehouse(
    df,
    lakehouse_name="SilverLakehouse",
    relative_path="sales_clean",
    mode="overwrite",
    partition_by=["year", "month"],   # optional
)

# Write path normalization:
# - "sales_clean"      -> Tables/dbo/sales_clean
# - "dbo/sales_clean"  -> Tables/dbo/sales_clean
# - "Tables/sales_clean" -> Tables/dbo/sales_clean
# - "Files/archive/sales_clean" stays unchanged

Merge (upsert) into a Delta table

ft.merge_lakehouse(
    source_df=new_df,
    lakehouse_name="SilverLakehouse",
    relative_path="sales_clean",
    merge_condition="src.id = tgt.id",
    # update_set and insert_set are optional:
    # omit them to update/insert all columns automatically
)

Clean data (generic)

clean_df = ft.clean_data(df)

By default it:

• normalizes columns to unique snake_case
• trims string values
• converts blank strings to null
• removes exact duplicates
• drops rows where all fields are null

Scan data quality issues

scan_output = ft.scan_data_errors(df, include_samples=True)

# The function displays the summary DataFrame and chart automatically by default.
# You can disable rendering with display_results=False.
scan_output = ft.scan_data_errors(df, include_samples=True, display_results=False)

# Spark DataFrame with all scan information (dataset metrics, per-column details, collisions)
scan_output["summary_df"].show(truncate=False)

# Plotly figure (auto bar/pie depending on issue categories)
scan_output["figure"].show()

# Optional helpers
print(scan_output["issue_totals"])
print(scan_output["collisions"])

scan_data_errors now returns a user-friendly bundle with a tabular summary DataFrame and a Plotly chart.

Add Silver metadata + date partitions

silver_df = ft.add_silver_metadata(
    df,
    source_lakehouse_name="RawLakehouse",
    source_relative_path="sales/raw",
    source_layer="bronze",  # optional
)

By default this adds:

• ingestion_timestamp
• source_layer
• source_path (resolved candidate path actually used for source read)
• year, month, day

Read -> clean -> write in one call

clean_df = ft.clean_and_write_data(
    source_lakehouse_name="RawLakehouse",
    source_relative_path="sales/raw",
    target_lakehouse_name="CuratedLakehouse",
    target_relative_path="sales/clean",
    mode="overwrite",
    partition_by=["year"],  # optional override
)

When partition_by is omitted, the helper writes with default partitions: ["year", "month", "day"].

Bulk clean all Lakehouse tables

bulk_result = ft.clean_and_write_all_tables(
    source_lakehouse_name="RawLakehouse",
    target_lakehouse_name="CuratedLakehouse",
    mode="overwrite",
    include_schemas=["dbo", "sales"],   # optional
    exclude_tables=["dbo.audit_log"],   # optional: accepts "table" or "schema.table"
    continue_on_error=True,             # optional
)

print(bulk_result["successful_tables"], bulk_result["failed_tables"])

The helper scans Tables/<schema>/<table> in the source Lakehouse and writes to the same relative path in the target Lakehouse.

Source -> Prepared pipeline (independent steps)

Each phase can be called independently, or orchestrated by helpers.

# 1) Discovery
schema_hash = ft.snapshot_source_schema(
    source_lakehouse_name="CleanLakehouse",
    source_relative_path="Tables/dbo/orders_clean",
)

# 2) Resolver (3 layers + unresolved audit)
source_df = ft.read_lakehouse("CleanLakehouse", "Tables/dbo/orders_clean")
mappings = ft.resolve_columns(
    df=source_df,
    source_lakehouse_name="CleanLakehouse",
    schema_hash=schema_hash,
    sample_size=500,
    profiling_confidence_threshold=0.80,
)

# 3) Transformation
prepared_df = ft.transform_to_prepared(
    df=source_df,
    resolved_mappings=mappings,
    source_lakehouse_name="CleanLakehouse",
)

# 4) Write + optimization
ft.write_prepared_table(
    df=prepared_df,
    resolved_mappings=mappings,
    target_lakehouse_name="BusinessReadyLakehouse",
    target_relative_path="Tables/dbo/orders_prepared",
    mode="overwrite",
)

# 5) Optional BI outputs
agg_tables = ft.generate_prepared_aggregations(
    source_lakehouse_name="CleanLakehouse",
    target_lakehouse_name="BusinessReadyLakehouse",
    target_relative_path="Tables/dbo/orders_prepared",
    resolved_mappings=mappings,
)

Config tables for this pipeline are stored in the source lakehouse under Tables/config/:

• source_schema_snapshot
• prefix_rules
• profiling_cache
• mapping_rules
• code_labels
• pipeline_audit_log

Orchestration helpers:

# Single table
prepared_df = ft.prepare_and_write_data(
    source_lakehouse_name="CleanLakehouse",
    source_relative_path="Tables/dbo/orders_clean",
    target_lakehouse_name="BusinessReadyLakehouse",
    target_relative_path="Tables/dbo/orders_prepared",
    mode="overwrite",
)

# Bulk mode (same pattern as clean_and_write_all_tables)
result = ft.prepare_and_write_all_tables(
    source_lakehouse_name="CleanLakehouse",
    target_lakehouse_name="BusinessReadyLakehouse",
    mode="overwrite",
    include_schemas=["dbo"],
    continue_on_error=True,
)
print(result["successful_tables"], result["failed_tables"])

You can also drive the orchestration with an explicit TABLES_CONFIG:

TABLES_CONFIG = [
    {
        "bronze_path": "Tables/dbo/fact_sale",
        "silver_table": "Tables/dbo/fact_sale",
        "partition_by": [],
        "mode": "overwrite",  # overwrite | append | merge
    },
    {
        "bronze_path": "Tables/dbo/dimension_customer",
        "silver_table": "Tables/dbo/dimension_customer",
        "partition_by": [],
        "mode": "append",
    },
    {
        "bronze_path": "Tables/dbo/fact_sale_updates",
        "silver_table": "Tables/dbo/fact_sale",
        "partition_by": [],
        "mode": "merge",
        "merge_condition": "src.sale_id = tgt.sale_id",  # required when mode='merge'
    },
]

bulk_result = ft.clean_and_write_all_tables(
    source_lakehouse_name="RawLakehouse",
    target_lakehouse_name="CuratedLakehouse",
    tables_config=TABLES_CONFIG,
    continue_on_error=True,
)

tables_config keys:

• bronze_path (required): source relative path in Lakehouse.
• silver_table (required): target relative path in Lakehouse.
• partition_by (optional): partition columns used by overwrite/append writes.
• mode (required): overwrite, append, or merge.
• merge_condition (required when mode="merge"): join condition used by Delta merge.

With explicit column mappings:

ft.merge_lakehouse(
    source_df=new_df,
    lakehouse_name="SilverLakehouse",
    relative_path="sales_clean",
    merge_condition="src.id = tgt.id",
    update_set={"amount": "src.amount", "updated_at": "src.updated_at"},
    insert_set={"id": "src.id", "amount": "src.amount", "updated_at": "src.updated_at"},
)

Read from a Warehouse

df = ft.read_warehouse("MyWarehouse", "SELECT * FROM dbo.sales WHERE year = 2024")

Write to a Warehouse

ft.write_warehouse(
    df,
    warehouse_name="MyWarehouse",
    table="dbo.sales_clean",
    mode="overwrite",       # or "append"
    batch_size=10_000,      # optional, default 10 000
)

Generate dimension tables

dims = ft.generate_dimensions(
    lakehouse_name="CuratedLakehouse",
    warehouse_name="MyWarehouse",
    include_date=True,
    include_country=True,
    include_city=True,
    # Optional range for dimension_date; defaults to rolling -10y / +2y
    start_date="2015-01-01",
    end_date="2030-12-31",
    # Optional fiscal year start month for dimension_date (1=Jan ... 12=Dec)
    fiscal_year_start_month=1,
    # Optional controls for countrystatecity-countries source
    countries_limit=None,
    include_states_metadata=True,
    fail_on_source_error=True,
    # Optional city filters (narrow down which cities are generated)
    city_regions=["Europe"],                   # filter by region
    city_subregions=["Western Europe"],        # filter by subregion
    city_countries=["FR", "DEU", "Belgium"],   # filter by code2/code3/name
)

# Access generated DataFrames
dims["dimension_date"].show(5)
dims["dimension_country"].show(5)
dims["dimension_city"].show(5)

dimension_city now includes country attributes: country_code_3, country_key, region, and subregion.

You can also filter cities directly via build_dimension_city:

city_df = ft.build_dimension_city(
    regions=["Americas"],
    countries=["US", "CAN"],
)

Filters accept case-insensitive values and are combined with AND logic. The countries parameter accepts any mix of country_code_2, country_code_3, or country_name.

dimension_date also includes calendar/fiscal attributes and labels:

• short_month, calendar_year, calendar_month
• fiscal_year, fiscal_month (from fiscal_year_start_month, default 1)
• calendar_year_label, calendar_month_label (format: CYyyyy-MMM)
• fiscal_year_label, fiscal_month_label (format: FYyyyy-MMM)
• iso_week_number

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API reference

Lakehouse

Function	Description
read_lakehouse(lakehouse_name, relative_path, spark=None)	Read a dataset — auto-detects Delta / Parquet / CSV
write_lakehouse(df, lakehouse_name, relative_path, mode, partition_by, format, spark=None)	Write a DataFrame (default: Delta, overwrite)
merge_lakehouse(source_df, lakehouse_name, relative_path, merge_condition, update_set, insert_set, spark=None)	Upsert via Delta merge
clean_data(df, drop_duplicates, drop_all_null_rows)	Apply standard generic cleaning to a DataFrame
add_silver_metadata(df, source_lakehouse_name, source_relative_path, source_layer, ingestion_timestamp_col, source_layer_col, source_path_col, year_col, month_col, day_col, spark=None)	Add Silver metadata and date partition columns, with resolved source path
scan_data_errors(df, include_samples)	Report common data-quality issues
clean_and_write_data(source_lakehouse_name, source_relative_path, target_lakehouse_name, target_relative_path, mode, partition_by, spark=None)	Read, clean, add Silver metadata, and write in one helper
clean_and_write_all_tables(source_lakehouse_name, target_lakehouse_name, mode, partition_by, tables_config, include_schemas, exclude_tables, continue_on_error, spark=None)	Discover tables or use config entries, then clean/write or merge per table

Warehouse

Function	Description
read_warehouse(warehouse_name, query, spark=None)	Run a SQL query, return a DataFrame
write_warehouse(df, warehouse_name, table, mode, batch_size, spark=None)	Write to a Warehouse table via JDBC

Dimensions

Function	Description
build_dimension_date(start_date=None, end_date=None, fiscal_year_start_month=1, lakehouse_name=None, lakehouse_relative_path=None, mode="overwrite", spark=None)	Build a date dimension DataFrame (with calendar/fiscal columns, labels, ISO week number) and optionally write it to Lakehouse
build_dimension_country(countries_limit=None, fail_on_source_error=True, lakehouse_name=None, lakehouse_relative_path=None, mode="overwrite", spark=None)	Build country dimension and optionally write it to Lakehouse
build_dimension_city(countries_limit=None, include_states_metadata=True, fail_on_source_error=True, regions=None, subregions=None, countries=None, lakehouse_name=None, lakehouse_relative_path=None, mode="overwrite", spark=None)	Build city dimension (with country attributes, plus optional region/subregion/country filters) and optionally write it to Lakehouse
generate_dimensions(lakehouse_name, warehouse_name, ..., city_regions=None, city_subregions=None, city_countries=None, ...)	Build and write selected dimensions to Lakehouse and Warehouse

Source to Prepared

Function	Description
snapshot_source_schema(source_lakehouse_name, source_relative_path, spark=None)	Passive profiling of source table + schema hash generation
resolve_columns(df, source_lakehouse_name, schema_hash=None, sample_size=500, profiling_confidence_threshold=0.80, unresolved_webhook_url=None, spark=None)	3-layer semantic resolver with confidence score and unresolved fallback audit
transform_to_prepared(df, resolved_mappings, source_lakehouse_name, spark=None)	Apply semantic casts, code labels, and date-derived columns in one select pass
write_prepared_table(df, resolved_mappings, target_lakehouse_name, target_relative_path, mode="overwrite", max_partitions_guard=500, vacuum_retention_hours=168, spark=None)	Write prepared table with partition strategy and conditional maintenance
generate_prepared_aggregations(source_lakehouse_name, target_lakehouse_name, target_relative_path, resolved_mappings, spark=None)	Build default prepared aggregations (prepared_agg_jour, prepared_agg_semaine, prepared_agg_region)
publish_semantic_model(target_lakehouse_name, agg_tables, resolved_mappings, power_bi_workspace_id, power_bi_token, spark=None)	Publish/update semantic model via Power BI/Fabric REST API
prepare_and_write_data(source_lakehouse_name, source_relative_path, target_lakehouse_name, target_relative_path, ...)	End-to-end orchestration for one table
prepare_and_write_all_tables(source_lakehouse_name, target_lakehouse_name, ...)	Bulk orchestration with discovery or explicit table config

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How path resolution works

lakehouse_name="BronzeLakehouse"
       │
       ▼
notebookutils.lakehouse.get("BronzeLakehouse")
       │
       ▼
lh.properties.abfsPath
= "abfss://bronze@<account>.dfs.core.windows.net"
       │
       ▼
full_path = abfsPath + "/" + relative_path

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Running the tests

pip install "fabrictools[dev]"
pytest

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Publishing to PyPI

See docs/PYPI_PUBLISH.md for a step-by-step guide.

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License

MIT